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Change-Id: Ib3d885189fafb41c416e352d6fed66851efe1977 Implements: blueprint use-openstack-command
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User-Facing Operations
This guide is for OpenStack operators and does not seek to be an exhaustive reference for users, but as an operator, you should have a basic understanding of how to use the cloud facilities. This chapter looks at OpenStack from a basic user perspective, which helps you understand your users' needs and determine, when you get a trouble ticket, whether it is a user issue or a service issue. The main concepts covered are images, flavors, security groups, block storage, shared file system storage, and instances.
Images
OpenStack images can often be thought of as "virtual machine templates." Images can also be standard installation media such as ISO images. Essentially, they contain bootable file systems that are used to launch instances.
Adding Images
Several pre-made images exist and can easily be imported into the Image service. A common image to add is the CirrOS image, which is very small and used for testing purposes. To add this image, simply do:
$ wget http://download.cirros-cloud.net/0.3.4/cirros-0.3.4-x86_64-disk.img
$ openstack image create --file cirros-0.3.4-x86_64-disk.img \
--public --container-format bare \
--disk-format qcow2 "cirros image"The openstack image create command provides a large
set of options for working with your image. For example, the --min-disk option is
useful for images that require root disks of a certain size (for
example, large Windows images). To view these options, run:
$ openstack help image createThe location
option is important to note. It does not copy the entire image into the
Image service, but references an original location where the image can
be found. Upon launching an instance of that image, the Image service
accesses the image from the location specified.
The copy-from
option copies the image from the location specified into the
/var/lib/glance/images directory. The same thing is done
when using the STDIN redirection with <, as shown in the example.
Run the following command to view the properties of existing images:
$ openstack image show <image-uuid>Adding Signed Images
To provide a chain of trust from an end user to the Image service,
and the Image service to Compute, an end user can import signed images
into the Image service that can be verified in Compute. Appropriate
Image service properties need to be set to enable signature
verification. Currently, signature verification is provided in Compute
only, but an accompanying feature in the Image service is targeted for
Mitaka.
Note
Prior to the steps below, an asymmetric keypair and certificate must be generated. In this example, these are called private_key.pem and new_cert.crt, respectively, and both reside in the current directory. Also note that the image in this example is cirros-0.3.4-x86_64-disk.img, but any image can be used.
The following are steps needed to create the signature used for the signed images:
Retrieve image for upload
$ wget http://download.cirros-cloud.net/0.3.4/cirros-0.3.4-x86_64-disk.imgUse private key to create a signature of the image
Note
The following implicit values are being used to create the signature in this example:
- Signature hash method = SHA-256
- Signature key type = RSA-PSS
Note
The following options are currently supported:
- Signature hash methods: SHA-224, SHA-256, SHA-384, and SHA-512
- Signature key types: DSA, ECC_SECT571K1, ECC_SECT409K1, ECC_SECT571R1, ECC_SECT409R1, ECC_SECP521R1, ECC_SECP384R1, and RSA-PSS
Generate signature of image and convert it to a base64 representation:
$ openssl dgst -sha256 -sign private_key.pem -sigopt rsa_padding_mode:pss \ -out image-file.signature cirros-0.3.4-x86_64-disk.img $ base64 image-file.signature > signature_64 $ cat signature_64 'c4br5f3FYQV6Nu20cRUSnx75R/VcW3diQdsUN2nhPw+UcQRDoGx92hwMgRxzFYeUyydRTWCcUS2ZLudPR9X7rM THFInA54Zj1TwEIbJTkHwlqbWBMU4+k5IUIjXxHO6RuH3Z5f/SlSt7ajsNVXaIclWqIw5YvEkgXTIEuDPE+C4='Create context
$ python >>> from keystoneclient.v3 import client >>> keystone_client = client.Client(username='demo', user_domain_name='Default', password='password', project_name='demo', auth_url='http://localhost:5000/v3') >>> from oslo_context import context >>> context = context.RequestContext(auth_token=keystone_client.auth_token, tenant=keystone_client.project_id)Encode certificate in DER format
>>> from cryptography import x509 as cryptography_x509 >>> from cryptography.hazmat import backends >>> from cryptography.hazmat.primitives import serialization >>> with open("new_cert.crt", "rb") as cert_file: >>> cert = cryptography_x509.load_pem_x509_certificate( cert_file.read(), backend=backends.default_backend() ) >>> certificate_der = cert.public_bytes(encoding=serialization.Encoding.DER)Upload Certificate in DER format to Castellan
>>> from castellan.common.objects import x_509 >>> from castellan import key_manager >>> castellan_cert = x_509.X509(certificate_der) >>> key_API = key_manager.API() >>> cert_uuid = key_API.store(context, castellan_cert) >>> cert_uuid u'62a33f41-f061-44ba-9a69-4fc247d3bfce'Upload Image to Image service, with Signature Metadata
Note
The following signature properties are used:
- img_signature uses the signature called signature_64
- img_signature_certificate_uuid uses the value from cert_uuid in section 5 above
- img_signature_hash_method matches 'SHA-256' in section 2 above
- img_signature_key_type matches 'RSA-PSS' in section 2 above
$ . openrc demo $ export OS_IMAGE_API_VERSION=2 $ openstack image create --property name=cirrosSignedImage_goodSignature \ --property is-public=true --container-format bare --disk-format qcow2 \ --property img_signature='c4br5f3FYQV6Nu20cRUSnx75R/VcW3diQdsUN2nhPw+UcQRDoGx92hwMgRxzFYeUyydRTWCcUS2ZLudPR9X7rMTHFInA54Zj1TwEIbJTkHwlqbWBMU4+k5IUIjXxHO6RuH3Z5fSlSt7ajsNVXaIclWqIw5YvEkgXTIEuDPE+C4=' \ --property img_signature_certificate_uuid='62a33f41-f061-44ba-9a69-4fc247d3bfce' \ --property img_signature_hash_method='SHA-256' \ --property img_signature_key_type='RSA-PSS' < ~/cirros-0.3.4-x86_64-disk.imgSignature verification will occur when Compute boots the signed image
Note
As of the Mitaka release, Compute supports instance signature validation. This is enabled by setting the
verify_glance_signaturesflag in nova.conf to TRUE. When enabled, Compute will automatically validate signed instances prior to its launch.
Sharing Images Between Projects
In a multi-tenant cloud environment, users sometimes want to share
their personal images or snapshots with other projects. This can be done
on the command line with the glance tool by the owner of
the image.
To share an image or snapshot with another project, do the following:
Obtain the UUID of the image:
$ openstack image listObtain the UUID of the project with which you want to share your image, let's call it target project. Unfortunately, non-admin users are unable to use the
openstackcommand to do this. The easiest solution is to obtain the UUID either from an administrator of the cloud or from a user located in the target project.Once you have both pieces of information, run the
glance member-createcommand:$ glance member-create <image-uuid> <project-uuid>For example:
$ glance member-create 733d1c44-a2ea-414b-aca7-69decf20d810 \ 771ed149ef7e4b2b88665cc1c98f77caYou now need to act in the target project scope.
Note
You will not see the shared image yet. Therefore the sharing needs to be accepted.
To accept the sharing, you need to update the member status:
$ glance member-update <image-uuid> <project-uuid> acceptedFor example:
$ glance member-update 733d1c44-a2ea-414b-aca7-69decf20d810 \ 771ed149ef7e4b2b88665cc1c98f77ca acceptedProject
771ed149ef7e4b2b88665cc1c98f77cawill now have access to image733d1c44-a2ea-414b-aca7-69decf20d810.Tip
You can explicitly ask for pending member status to view shared images not yet accepted:
$ glance image-list --member-status pending
Deleting Images
To delete an image, just execute:
$ openstack image delete <image uuid>Caution
Generally, deleting an image does not affect instances or snapshots that were based on the image. However, some drivers may require the original image to be present to perform a migration. For example, XenAPI live-migrate will work fine if the image is deleted, but libvirt will fail.
Other CLI Options
A full set of options can be found using:
$ glance helpor the Command-Line Interface Reference.
The Image service and the Database
The only thing the Image service does not store in a database is the image itself. The Image service database has two main tables:
imagesimage_properties
Working directly with the database and SQL queries can provide you with custom lists and reports of images. Technically, you can update properties about images through the database, although this is not generally recommended.
Example Image service Database Queries
One interesting example is modifying the table of images and the owner of that image. This can be easily done if you simply display the unique ID of the owner. This example goes one step further and displays the readable name of the owner:
mysql> select glance.images.id,
glance.images.name, keystone.tenant.name, is_public from
glance.images inner join keystone.tenant on
glance.images.owner=keystone.tenant.id;Another example is displaying all properties for a certain image:
mysql> select name, value from
image_properties where id = <image_id>Flavors
Virtual hardware templates are called "flavors" in OpenStack, defining sizes for RAM, disk, number of cores, and so on. The default install provides five flavors.
These are configurable by admin users (the rights may also be
delegated to other users by redefining the access controls for
compute_extension:flavormanage in
/etc/nova/policy.json on the nova-api server).
To get the list of available flavors on your system, run:
$ openstack flavor list
+----+-----------+-------+------+-----------+-------+-----------+
| ID | Name | RAM | Disk | Ephemeral | VCPUs | Is Public |
+----+-----------+-------+------+-----------+-------+-----------+
| 1 | m1.tiny | 512 | 1 | 0 | 1 | True |
| 2 | m1.small | 2048 | 20 | 0 | 1 | True |
| 3 | m1.medium | 4096 | 40 | 0 | 2 | True |
| 4 | m1.large | 8192 | 80 | 0 | 4 | True |
| 5 | m1.xlarge | 16384 | 160 | 0 | 8 | True |
+----+-----------+-------+------+-----------+-------+-----------+The openstack flavor create command allows authorized
users to create new flavors. Additional flavor manipulation commands can
be shown with the following command:
$ openstack help | grep flavorFlavors define a number of parameters, resulting in the user having a
choice of what type of virtual machine to run—just like they would have
if they were purchasing a physical server. table_flavor_params lists the
elements that can be set. Note in particular extra_specs,
which can be used to define free-form characteristics, giving a lot of
flexibility beyond just the size of RAM, CPU, and Disk.
| Column | Description |
|---|---|
| ID | Unique ID (integer or UUID) for the flavor. |
| Name | A descriptive name, such as xx.size_name, is conventional but not required, though some third-party tools may rely on it. |
| Memory_MB | Virtual machine memory in megabytes. |
| Disk | Virtual root disk size in gigabytes. This is an ephemeral disk the base image is copied into. You don't use it when you boot from a persistent volume. The "0" size is a special case that uses the native base image size as the size of the ephemeral root volume. |
| Ephemeral | Specifies the size of a secondary ephemeral data disk. This is an empty, unformatted disk and exists only for the life of the instance. |
| Swap | Optional swap space allocation for the instance. |
| VCPUs | Number of virtual CPUs presented to the instance. |
| RXTX_Factor | Optional property that allows created servers to have a different bandwidth cap from that defined in the network they are attached to. This factor is multiplied by the rxtx_base property of the network. Default value is 1.0 (that is, the same as the attached network). |
| Is_Public | Boolean value that indicates whether the flavor is available to all
users or private. Private flavors do not get the current tenant assigned
to them. Defaults to True. |
| extra_specs | Additional optional restrictions on which compute nodes the flavor can run on. This is implemented as key-value pairs that must match against the corresponding key-value pairs on compute nodes. Can be used to implement things like special resources (such as flavors that can run only on compute nodes with GPU hardware). |
Private Flavors
A user might need a custom flavor that is uniquely tuned for a
project she is working on. For example, the user might require 128 GB of
memory. If you create a new flavor as described above, the user would
have access to the custom flavor, but so would all other tenants in your
cloud. Sometimes this sharing isn't desirable. In this scenario,
allowing all users to have access to a flavor with 128 GB of memory
might cause your cloud to reach full capacity very quickly. To prevent
this, you can restrict access to the custom flavor using the nova flavor-access-add
command:
$ nova flavor-access-add <flavor-id> <project-id>To view a flavor's access list, do the following:
$ nova flavor-access-list [--flavor <flavor-id>]Tip
Once access to a flavor has been restricted, no other projects besides the ones granted explicit access will be able to see the flavor. This includes the admin project. Make sure to add the admin project in addition to the original project.
It's also helpful to allocate a specific numeric range for custom and private flavors. On UNIX-based systems, nonsystem accounts usually have a UID starting at 500. A similar approach can be taken with custom flavors. This helps you easily identify which flavors are custom, private, and public for the entire cloud.
How Do I Modify an Existing Flavor?
The OpenStack dashboard simulates the ability to modify a flavor by deleting an existing flavor and creating a new one with the same name.
Security Groups
A common new-user issue with OpenStack is failing to set an appropriate security group when launching an instance. As a result, the user is unable to contact the instance on the network.
Security groups are sets of IP filter rules that are applied to an instance's networking. They are project specific, and project members can edit the default rules for their group and add new rules sets. All projects have a "default" security group, which is applied to instances that have no other security group defined. Unless changed, this security group denies all incoming traffic.
General Security Groups Configuration
The nova.conf option allow_same_net_traffic
(which defaults to true) globally controls whether the
rules apply to hosts that share a network. When set to
true, hosts on the same subnet are not filtered and are
allowed to pass all types of traffic between them. On a flat network,
this allows all instances from all projects unfiltered communication.
With VLAN networking, this allows access between instances within the
same project. If allow_same_net_traffic is set to
false, security groups are enforced for all connections. In
this case, it is possible for projects to simulate
allow_same_net_traffic by configuring their default
security group to allow all traffic from their subnet.
Tip
As noted in the previous chapter, the number of rules per security
group is controlled by the quota_security_group_rules, and
the number of allowed security groups per project is controlled by the
quota_security_groups quota.
End-User Configuration of Security Groups
Security groups for the current project can be found on the OpenStack
dashboard under Access & Security. To see details of an
existing group, select the Edit Security Group action for that security
group. Obviously, modifying existing groups can be done from this edit
interface. There is a Create Security Group button on the main Access & Security
page for creating new groups. We discuss the terms used in these fields
when we explain the command-line equivalents.
Setting with openstack command
If your environment is using Neutron, you can configure security
groups settings using the openstack command. Get a list of security groups
for the project you are acting in, by using following command:
$ openstack security group list
+------------------------+---------+------------------------+-------------------------+
| ID | Name | Description | Project |
+------------------------+---------+------------------------+-------------------------+
| 3bef30ed-442d-4cf1 | default | Default security group | 35e3820f7490493ca9e3a5e |
| -b84d-2ba50a395599 | | | 685393298 |
| aaf1d0b7-98a0-41a3-ae1 | default | Default security group | 32e9707393c34364923edf8 |
| 6-a58b94503289 | | | f5029cbfe |
+------------------------+---------+------------------------+-------------------------+To view the details of a security group:
$ openstack security group show 3bef30ed-442d-4cf1-b84d-2ba50a395599
+-----------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Field | Value |
+-----------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| created_at | 2016-11-08T21:55:19Z |
| description | Default security group |
| id | 3bef30ed-442d-4cf1-b84d-2ba50a395599 |
| name | default |
| project_id | 35e3820f7490493ca9e3a5e685393298 |
| project_id | 35e3820f7490493ca9e3a5e685393298 |
| revision_number | 1 |
| rules | created_at='2016-11-08T21:55:19Z', direction='egress', ethertype='IPv6', id='1dca4cac-d4f2-46f5-b757-d53c01a87bdf', project_id='35e3820f7490493ca9e3a5e685393298', |
| | revision_number='1', updated_at='2016-11-08T21:55:19Z' |
| | created_at='2016-11-08T21:55:19Z', direction='egress', ethertype='IPv4', id='2d83d6f2-424e-4b7c-b9c4-1ede89c00aab', project_id='35e3820f7490493ca9e3a5e685393298', |
| | revision_number='1', updated_at='2016-11-08T21:55:19Z' |
| | created_at='2016-11-08T21:55:19Z', direction='ingress', ethertype='IPv4', id='62b7d1eb-b98d-4707-a29f-6df379afdbaa', project_id='35e3820f7490493ca9e3a5e685393298', remote_group_id |
| | ='3bef30ed-442d-4cf1-b84d-2ba50a395599', revision_number='1', updated_at='2016-11-08T21:55:19Z' |
| | created_at='2016-11-08T21:55:19Z', direction='ingress', ethertype='IPv6', id='f0d4b8d6-32d4-4f93-813d-3ede9d698fbb', project_id='35e3820f7490493ca9e3a5e685393298', remote_group_id |
| | ='3bef30ed-442d-4cf1-b84d-2ba50a395599', revision_number='1', updated_at='2016-11-08T21:55:19Z' |
| updated_at | 2016-11-08T21:55:19Z |
+-----------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+These rules are all "allow" type rules, as the default is deny. This example shows the full port range for all protocols allowed from all IPs. This section describes the most common security group rule parameters:
- direction
-
The direction in which the security group rule is applied. Valid values are
ingressoregress. - remote_ip_prefix
-
This attribute value matches the specified IP prefix as the source IP address of the IP packet.
- protocol
-
The protocol that is matched by the security group rule. Valid values are
null,tcp,udp,icmp, andicmpv6. - port_range_min
-
The minimum port number in the range that is matched by the security group rule. If the protocol is TCP or UDP, this value must be less than or equal to the
port_range_maxattribute value. If the protocol is ICMP or ICMPv6, this value must be an ICMP or ICMPv6 type, respectively. - port_range_max
-
The maximum port number in the range that is matched by the security group rule. The
port_range_minattribute constrains theport_range_maxattribute. If the protocol is ICMP or ICMPv6, this value must be an ICMP or ICMPv6 type, respectively. - ethertype
-
Must be
IPv4orIPv6, and addresses represented in CIDR must match the ingress or egress rules.
When adding a new security group, you should pick a descriptive but
brief name. This name shows up in brief descriptions of the instances
that use it where the longer description field often does not. Seeing
that an instance is using security group http is much
easier to understand than bobs_group or
secgrp1.
This example creates a security group that allows web traffic
anywhere on the Internet. We'll call this group
global_http, which is clear and reasonably concise,
encapsulating what is allowed and from where. From the command line,
do:
$ openstack security group create global_http --description "allow web traffic from the Internet"
Created a new security_group:
+-----------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Field | Value |
+-----------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| created_at | 2016-11-10T16:09:18Z |
| description | allow web traffic from the Internet |
| headers | |
| id | 70675447-1b92-4102-a7ea-6a3ca99d2290 |
| name | global_http |
| project_id | 32e9707393c34364923edf8f5029cbfe |
| project_id | 32e9707393c34364923edf8f5029cbfe |
| revision_number | 1 |
| rules | created_at='2016-11-10T16:09:18Z', direction='egress', ethertype='IPv4', id='e440b13a-e74f-4700-a36f-9ecc0de76612', project_id='32e9707393c34364923edf8f5029cbfe', |
| | revision_number='1', updated_at='2016-11-10T16:09:18Z' |
| | created_at='2016-11-10T16:09:18Z', direction='egress', ethertype='IPv6', id='0debf8cb-9f1d-45e5-98db-ee169c0715fe', project_id='32e9707393c34364923edf8f5029cbfe', |
| | revision_number='1', updated_at='2016-11-10T16:09:18Z' |
| updated_at | 2016-11-10T16:09:18Z |
+-----------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+Immediately after create, the security group has only an allow egress rule. To make it do what we want, we need to add some rules:
$ openstack security group rule create --help
usage: openstack security group rule create [-h]
[-f {json,shell,table,value,yaml}]
[-c COLUMN]
[--max-width <integer>]
[--noindent] [--prefix PREFIX]
[--remote-ip <ip-address> | --remote-group <group>]
[--dst-port <port-range>]
[--icmp-type <icmp-type>]
[--icmp-code <icmp-code>]
[--protocol <protocol>]
[--ingress | --egress]
[--ethertype <ethertype>]
[--project <project>]
[--project-domain <project-domain>]
<group>
$ openstack security group rule create --ingress --ethertype IPv4 \
--protocol tcp --remote-ip 0.0.0.0/0 global_http
Created a new security group rule:
+-------------------+--------------------------------------+
| Field | Value |
+-------------------+--------------------------------------+
| created_at | 2016-11-10T16:12:27Z |
| description | |
| direction | ingress |
| ethertype | IPv4 |
| headers | |
| id | 694d30b1-1c4d-4bb8-acbe-7f1b3de2b20f |
| port_range_max | None |
| port_range_min | None |
| project_id | 32e9707393c34364923edf8f5029cbfe |
| project_id | 32e9707393c34364923edf8f5029cbfe |
| protocol | tcp |
| remote_group_id | None |
| remote_ip_prefix | 0.0.0.0/0 |
| revision_number | 1 |
| security_group_id | 70675447-1b92-4102-a7ea-6a3ca99d2290 |
| updated_at | 2016-11-10T16:12:27Z |
+-------------------+--------------------------------------+Despite only outputting the newly added rule, this operation is additive:
$ openstack security group show global_http
+-----------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Field | Value |
+-----------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| created_at | 2016-11-10T16:09:18Z |
| description | allow web traffic from the Internet |
| id | 70675447-1b92-4102-a7ea-6a3ca99d2290 |
| name | global_http |
| project_id | 32e9707393c34364923edf8f5029cbfe |
| project_id | 32e9707393c34364923edf8f5029cbfe |
| revision_number | 2 |
| rules | created_at='2016-11-10T16:09:18Z', direction='egress', ethertype='IPv6', id='0debf8cb-9f1d-45e5-98db-ee169c0715fe', project_id='32e9707393c34364923edf8f5029cbfe', |
| | revision_number='1', updated_at='2016-11-10T16:09:18Z' |
| | created_at='2016-11-10T16:12:27Z', direction='ingress', ethertype='IPv4', id='694d30b1-1c4d-4bb8-acbe-7f1b3de2b20f', project_id='32e9707393c34364923edf8f5029cbfe', protocol='tcp', |
| | remote_ip_prefix='0.0.0.0/0', revision_number='1', updated_at='2016-11-10T16:12:27Z' |
| | created_at='2016-11-10T16:09:18Z', direction='egress', ethertype='IPv4', id='e440b13a-e74f-4700-a36f-9ecc0de76612', project_id='32e9707393c34364923edf8f5029cbfe', |
| | revision_number='1', updated_at='2016-11-10T16:09:18Z' |
| updated_at | 2016-11-10T16:12:27Z |
+-----------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+The inverse operation is called openstack security group rule delete, specifying
security-group-rule ID. Whole security groups can be removed with openstack security group delete.
To create security group rules for a cluster of instances, use RemoteGroups.
RemoteGroups are a dynamic way of defining the CIDR of allowed sources. The user specifies a RemoteGroup (security group name) and then all the users' other instances using the specified RemoteGroup are selected dynamically. This dynamic selection alleviates the need for individual rules to allow each new member of the cluster.
The code is similar to the above example of openstack security group rule create. To use
RemoteGroup, specify --remote-group instead of --remote-ip. For
example:
$ openstack security group rule create --ingress \
--ethertype IPv4 --protocol tcp \
--remote-group global_http clusterThe "cluster" rule allows SSH access from any other instance that
uses the global-http group.
Block Storage
OpenStack volumes are persistent block-storage devices that may be attached and detached from instances, but they can be attached to only one instance at a time. Similar to an external hard drive, they do not provide shared storage in the way a network file system or object store does. It is left to the operating system in the instance to put a file system on the block device and mount it, or not.
As with other removable disk technology, it is important that the operating system is not trying to make use of the disk before removing it. On Linux instances, this typically involves unmounting any file systems mounted from the volume. The OpenStack volume service cannot tell whether it is safe to remove volumes from an instance, so it does what it is told. If a user tells the volume service to detach a volume from an instance while it is being written to, you can expect some level of file system corruption as well as faults from whatever process within the instance was using the device.
There is nothing OpenStack-specific in being aware of the steps
needed to access block devices from within the instance operating
system, potentially formatting them for first use and being cautious
when removing them. What is specific is how to create new volumes and
attach and detach them from instances. These operations can all be done
from the Volumes
page of the dashboard or by using the openstack
command-line client.
To add new volumes, you need only a volume size in gigabytes. Either
put these into the Create Volume web form or use the command
line:
$ openstack volume create volume1 --size 10This creates a 10 GB volume. To list existing volumes and the instances they are connected to, if any:
$ openstack volume list
+--------------------------------------+--------------+--------+------+-------------+
| ID | Display Name | Status | Size | Attached to |
+--------------------------------------+--------------+--------+------+-------------+
| 6cf4114a-56b2-476b-acf7-7359d8334aa2 | volume1 | error | 10 | |
+------------+-----------+-------------+------+-------------+----------+------------+OpenStack Block Storage also allows creating snapshots of volumes.
Remember that this is a block-level snapshot that is crash consistent,
so it is best if the volume is not connected to an instance when the
snapshot is taken and second best if the volume is not in use on the
instance it is attached to. If the volume is under heavy use, the
snapshot may have an inconsistent file system. In fact, by default, the
volume service does not take a snapshot of a volume that is attached to
an image, though it can be forced to. To take a volume snapshot, either
select Create Snapshot from the actions column next to
the volume name on the dashboard Volumes page, or run this from the command
line:
$ openstack help snapshot create
usage: openstack snapshot create [-h] [-f {json,shell,table,value,yaml}]
[-c COLUMN] [--max-width <integer>]
[--noindent] [--prefix PREFIX]
[--name <name>] [--description <description>]
[--force] [--property <key=value>]
<volume>
Create new snapshot
positional arguments:
<volume> Volume to snapshot (name or ID)
optional arguments:
-h, --help show this help message and exit
--name <name> Name of the snapshot
--description <description>
Description of the snapshot
--force Create a snapshot attached to an instance. Default is
False
--property <key=value>
Set a property to this snapshot (repeat option to set
multiple properties)
output formatters:
output formatter options
-f {json,shell,table,value,yaml}, --format {json,shell,table,value,yaml}
the output format, defaults to table
-c COLUMN, --column COLUMN
specify the column(s) to include, can be repeated
table formatter:
--max-width <integer>
Maximum display width, <1 to disable. You can also use
the CLIFF_MAX_TERM_WIDTH environment variable, but the
parameter takes precedence.
json formatter:
--noindent whether to disable indenting the JSON
shell formatter:
a format a UNIX shell can parse (variable="value")
--prefix PREFIX add a prefix to all variable namesNote
For more information about updating Block Storage volumes (for example, resizing or transferring), see the OpenStack End User Guide.
Block Storage Creation Failures
If a user tries to create a volume and the volume immediately goes into an error state, the best way to troubleshoot is to grep the cinder log files for the volume's UUID. First try the log files on the cloud controller, and then try the storage node where the volume was attempted to be created:
# grep 903b85d0-bacc-4855-a261-10843fc2d65b /var/log/cinder/*.logShared File Systems Service
Similar to Block Storage, the Shared File System is a persistent storage, called share, that can be used in multi-tenant environments. Users create and mount a share as a remote file system on any machine that allows mounting shares, and has network access to share exporter. This share can then be used for storing, sharing, and exchanging files. The default configuration of the Shared File Systems service depends on the back-end driver the admin chooses when starting the Shared File Systems service. For more information about existing back-end drivers, see Share Backends of Shared File Systems service Developer Guide. For example, in case of OpenStack Block Storage based back-end is used, the Shared File Systems service cares about everything, including VMs, networking, keypairs, and security groups. Other configurations require more detailed knowledge of shares functionality to set up and tune specific parameters and modes of shares functioning.
Shares are a remote mountable file system, so users can mount a share to multiple hosts, and have it accessed from multiple hosts by multiple users at a time. With the Shared File Systems service, you can perform a large number of operations with shares:
- Create, update, delete, and force-delete shares
- Change access rules for shares, reset share state
- Specify quotas for existing users or tenants
- Create share networks
- Define new share types
- Perform operations with share snapshots: create, change name, create a share from a snapshot, delete
- Operate with consistency groups
- Use security services
For more information on share management see Share management of chapter “Shared File Systems” in OpenStack Administrator Guide. As to Security services, you should remember that different drivers support different authentication methods, while generic driver does not support Security Services at all (see section Security services of chapter “Shared File Systems” in OpenStack Administrator Guide).
You can create a share in a network, list shares, and show information for, update, and delete a specified share. You can also create snapshots of shares (see Share snapshots of chapter “Shared File Systems” in OpenStack Administrator Guide).
There are default and specific share types that allow you to filter or choose back-ends before you create a share. Functions and behaviour of share type is similar to Block Storage volume type (see Share types of chapter “Shared File Systems” in OpenStack Administrator Guide).
To help users keep and restore their data, Shared File Systems service provides a mechanism to create and operate snapshots (see Share snapshots of chapter “Shared File Systems” in OpenStack Administrator Guide).
A security service stores configuration information for clients for authentication and authorization. Inside Manila a share network can be associated with up to three security types (for detailed information see Security services of chapter “Shared File Systems” in OpenStack Administrator Guide):
- LDAP
- Kerberos
- Microsoft Active Directory
Shared File Systems service differs from the principles implemented in Block Storage. Shared File Systems service can work in two modes:
- Without interaction with share networks, in so called "no share servers" mode.
- Interacting with share networks.
Networking service is used by the Shared File Systems service to directly operate with share servers. For switching interaction with Networking service on, create a share specifying a share network. To use "share servers" mode even being out of OpenStack, a network plugin called StandaloneNetworkPlugin is used. In this case, provide network information in the configuration: IP range, network type, and segmentation ID. Also you can add security services to a share network (see section “Networking” of chapter “Shared File Systems” in OpenStack Administrator Guide).
The main idea of consistency groups is to enable you to create snapshots at the exact same point in time from multiple file system shares. Those snapshots can be then used for restoring all shares that were associated with the consistency group (see section “Consistency groups” of chapter “Shared File Systems” in OpenStack Administrator Guide).
Shared File System storage allows administrators to set limits and quotas for specific tenants and users. Limits are the resource limitations that are allowed for each tenant or user. Limits consist of:
- Rate limits
- Absolute limits
Rate limits control the frequency at which users can issue specific API requests. Rate limits are configured by administrators in a config file. Also, administrator can specify quotas also known as max values of absolute limits per tenant. Whereas users can see only the amount of their consumed resources. Administrator can specify rate limits or quotas for the following resources:
- Max amount of space available for all shares
- Max number of shares
- Max number of shared networks
- Max number of share snapshots
- Max total amount of all snapshots
- Type and number of API calls that can be made in a specific time interval
User can see his rate limits and absolute limits by running commands
manila rate-limits
and manila absolute-limits respectively. For more
details on limits and quotas see Quotas
and limits of "Share management" section of OpenStack Administrator
Guide document.
This section lists several of the most important Use Cases that demonstrate the main functions and abilities of Shared File Systems service:
- Create share
- Operating with a share
- Manage access to shares
- Create snapshots
- Create a share network
- Manage a share network
Note
Shared File Systems service cannot warn you beforehand if it is safe to write a specific large amount of data onto a certain share or to remove a consistency group if it has a number of shares assigned to it. In such a potentially erroneous situations, if a mistake happens, you can expect some error message or even failing of shares or consistency groups into an incorrect status. You can also expect some level of system corruption if a user tries to unmount an unmanaged share while a process is using it for data transfer.
Create Share
In this section, we examine the process of creating a simple share. It consists of several steps:
- Check if there is an appropriate share type defined in the Shared File Systems service
- If such a share type does not exist, an Admin should create it using
manila type-createcommand before other users are able to use it - Using a share network is optional. However if you need one, check if
there is an appropriate network defined in Shared File Systems service
by using
manila share-network-listcommand. For the information on creating a share network, seecreate_a_share_networkbelow in this chapter. - Create a public share using
manila create. - Make sure that the share has been created successfully and is ready to use (check the share status and see the share export location)
Below is the same whole procedure described step by step and in more detail.
Note
Before you start, make sure that Shared File Systems service is installed on your OpenStack cluster and is ready to use.
By default, there are no share types defined in Shared File Systems service, so you can check if a required one has been already created:
$ manila type-list
+------+--------+-----------+-----------+----------------------------------+----------------------+
| ID | Name | Visibility| is_default| required_extra_specs | optional_extra_specs |
+------+--------+-----------+-----------+----------------------------------+----------------------+
| c0...| default| public | YES | driver_handles_share_servers:True| snapshot_support:True|
+------+--------+-----------+-----------+----------------------------------+----------------------+If the share types list is empty or does not contain a type you need, create the required share type using this command:
$ manila type-create netapp1 False --is_public TrueThis command will create a public share with the following
parameters: name = netapp1,
spec_driver_handles_share_servers = False
You can now create a public share with my_share_net network, default share type, NFS shared file systems protocol, and 1 GB size:
$ manila create nfs 1 --name "Share1" --description "My first share" \
--share-type default --share-network my_share_net --metadata aim=testing --public
+-----------------------------+--------------------------------------+
| Property | Value |
+-----------------------------+--------------------------------------+
| status | creating |
| share_type_name | default |
| description | My first share |
| availability_zone | None |
| share_network_id | 9c187d23-7e1d-4d91-92d0-77ea4b9b9496 |
| share_server_id | None |
| host | |
| access_rules_status | active |
| snapshot_id | None |
| is_public | True |
| task_state | None |
| snapshot_support | True |
| id | edd82179-587e-4a87-9601-f34b2ca47e5b |
| size | 1 |
| name | Share1 |
| share_type | e031d5e9-f113-491a-843f-607128a5c649 |
| has_replicas | False |
| replication_type | None |
| created_at | 2016-03-20T00:00:00.000000 |
| share_proto | NFS |
| consistency_group_id | None |
| source_cgsnapshot_member_id | None |
| project_id | e81908b1bfe8468abb4791eae0ef6dd9 |
| metadata | {u'aim': u'testing'} |
+-----------------------------+--------------------------------------+To confirm that creation has been successful, see the share in the share list:
$ manila list
+----+-------+-----+------------+-----------+-------------------------------+----------------------+
| ID | Name | Size| Share Proto| Share Type| Export location | Host |
+----+-------+-----+------------+-----------+-------------------------------+----------------------+
| a..| Share1| 1 | NFS | c0086... | 10.254.0.3:/shares/share-2d5..| manila@generic1#GEN..|
+----+-------+-----+------------+-----------+-------------------------------+----------------------+Check the share status and see the share export location. After
creation, the share status should become available:
$ manila show Share1
+-----------------------------+----------------------------------------------------------------------+
| Property | Value |
+-----------------------------+----------------------------------------------------------------------+
| status | available |
| share_type_name | default |
| description | My first share |
| availability_zone | nova |
| share_network_id | 9c187d23-7e1d-4d91-92d0-77ea4b9b9496 |
| export_locations | |
| | path = 10.254.0.3:/shares/share-18cb05be-eb69-4cb2-810f-91c75ef30f90 |
| | preferred = False |
| | is_admin_only = False |
| | id = d6a82c0d-36b0-438b-bf34-63f3932ddf4e |
| | share_instance_id = 18cb05be-eb69-4cb2-810f-91c75ef30f90 |
| | path = 10.0.0.3:/shares/share-18cb05be-eb69-4cb2-810f-91c75ef30f90 |
| | preferred = False |
| | is_admin_only = True |
| | id = 51672666-06b8-4741-99ea-64f2286f52e2 |
| | share_instance_id = 18cb05be-eb69-4cb2-810f-91c75ef30f90 |
| share_server_id | ea8b3a93-ab41-475e-9df1-0f7d49b8fa54 |
| host | manila@generic1#GENERIC1 |
| access_rules_status | active |
| snapshot_id | None |
| is_public | True |
| task_state | None |
| snapshot_support | True |
| id | e7364bcc-3821-49bf-82d6-0c9f0276d4ce |
| size | 1 |
| name | Share1 |
| share_type | e031d5e9-f113-491a-843f-607128a5c649 |
| has_replicas | False |
| replication_type | None |
| created_at | 2016-03-20T00:00:00.000000 |
| share_proto | NFS |
| consistency_group_id | None |
| source_cgsnapshot_member_id | None |
| project_id | e81908b1bfe8468abb4791eae0ef6dd9 |
| metadata | {u'aim': u'testing'} |
+-----------------------------+----------------------------------------------------------------------+The value is_public defines the level of visibility for
the share: whether other tenants can or cannot see the share. By
default, the share is private. Now you can mount the created share like
a remote file system and use it for your purposes.
Note
See Share Management of “Shared File Systems” section of OpenStack Administrator Guide document for the details on share management operations.
Manage Access To Shares
Currently, you have a share and would like to control access to this share for other users. For this, you have to perform a number of steps and operations. Before getting to manage access to the share, pay attention to the following important parameters. To grant or deny access to a share, specify one of these supported share access levels:
rw: read and write (RW) access. This is the default value.ro:read-only (RO) access.
Additionally, you should also specify one of these supported authentication methods:
ip: authenticates an instance through its IP address. A valid format is XX.XX.XX.XX orXX.XX.XX.XX/XX. For example 0.0.0.0/0.cert: authenticates an instance through a TLS certificate. Specify the TLS identity as the IDENTKEY. A valid value is any string up to 64 characters long in the common name (CN) of the certificate. The meaning of a string depends on its interpretation.user: authenticates by a specified user or group name. A valid value is an alphanumeric string that can contain some special characters and is from 4 to 32 characters long.
Note
Do not mount a share without an access rule! This can lead to an exception.
Allow access to the share with IP access type and 10.254.0.4 IP address:
$ manila access-allow Share1 ip 10.254.0.4 --access-level rw
+--------------+--------------------------------------+
| Property | Value |
+--------------+--------------------------------------+
| share_id | 7bcd888b-681b-4836-ac9c-c3add4e62537 |
| access_type | ip |
| access_to | 10.254.0.4 |
| access_level | rw |
| state | new |
| id | de715226-da00-4cfc-b1ab-c11f3393745e |
+--------------+--------------------------------------+Mount the Share:
$ sudo mount -v -t nfs 10.254.0.5:/shares/share-5789ddcf-35c9-4b64-a28a-7f6a4a574b6a /mnt/Then check if the share mounted successfully and according to the specified access rules:
$ manila access-list Share1
+--------------------------------------+-------------+------------+--------------+--------+
| id | access type | access to | access level | state |
+--------------------------------------+-------------+------------+--------------+--------+
| 4f391c6b-fb4f-47f5-8b4b-88c5ec9d568a | user | demo | rw | error |
| de715226-da00-4cfc-b1ab-c11f3393745e | ip | 10.254.0.4 | rw | active |
+--------------------------------------+-------------+------------+--------------+--------+Note
Different share features are supported by different share drivers. In
these examples there was used generic (Cinder as a back-end) driver that
does not support user and cert authentication
methods.
Tip
For the details of features supported by different drivers see Manila share features support mapping of Manila Developer Guide document.
Manage Shares
There are several other useful operations you would perform when working with shares.
Update Share
To change the name of a share, or update its description, or level of visibility for other tenants, use this command:
$ manila update Share1 --description "My first share. Updated" --is-public FalseCheck the attributes of the updated Share1:
$ manila show Share1
+-----------------------------+----------------------------------------------------------------------+
| Property | Value |
+-----------------------------+----------------------------------------------------------------------+
| status | available |
| share_type_name | default |
| description | My first share. Updated |
| availability_zone | nova |
| share_network_id | 9c187d23-7e1d-4d91-92d0-77ea4b9b9496 |
| export_locations | |
| | path = 10.254.0.3:/shares/share-18cb05be-eb69-4cb2-810f-91c75ef30f90 |
| | preferred = False |
| | is_admin_only = False |
| | id = d6a82c0d-36b0-438b-bf34-63f3932ddf4e |
| | share_instance_id = 18cb05be-eb69-4cb2-810f-91c75ef30f90 |
| | path = 10.0.0.3:/shares/share-18cb05be-eb69-4cb2-810f-91c75ef30f90 |
| | preferred = False |
| | is_admin_only = True |
| | id = 51672666-06b8-4741-99ea-64f2286f52e2 |
| | share_instance_id = 18cb05be-eb69-4cb2-810f-91c75ef30f90 |
| share_server_id | ea8b3a93-ab41-475e-9df1-0f7d49b8fa54 |
| host | manila@generic1#GENERIC1 |
| access_rules_status | active |
| snapshot_id | None |
| is_public | False |
| task_state | None |
| snapshot_support | True |
| id | e7364bcc-3821-49bf-82d6-0c9f0276d4ce |
| size | 1 |
| name | Share1 |
| share_type | e031d5e9-f113-491a-843f-607128a5c649 |
| has_replicas | False |
| replication_type | None |
| created_at | 2016-03-20T00:00:00.000000 |
| share_proto | NFS |
| consistency_group_id | None |
| source_cgsnapshot_member_id | None |
| project_id | e81908b1bfe8468abb4791eae0ef6dd9 |
| metadata | {u'aim': u'testing'} |
+-----------------------------+----------------------------------------------------------------------+Reset Share State
Sometimes a share may appear and then hang in an erroneous or a transitional state. Unprivileged users do not have the appropriate access rights to correct this situation. However, having cloud administrator's permissions, you can reset the share's state by using
$ manila reset-state [–state state] share_namecommand to reset share state, where state indicates which state to
assign the share to. Options include:
available, error, creating, deleting, error_deleting
states.
After running
$ manila reset-state Share2 --state deletingcheck the share's status:
$ manila show Share2
+-----------------------------+-------------------------------------------+
| Property | Value |
+-----------------------------+-------------------------------------------+
| status | deleting |
| share_type_name | default |
| description | share from a snapshot. |
| availability_zone | nova |
| share_network_id | 5c3cbabb-f4da-465f-bc7f-fadbe047b85a |
| export_locations | [] |
| share_server_id | 41b7829d-7f6b-4c96-aea5-d106c2959961 |
| host | manila@generic1#GENERIC1 |
| snapshot_id | 962e8126-35c3-47bb-8c00-f0ee37f42ddd |
| is_public | False |
| task_state | None |
| snapshot_support | True |
| id | b6b0617c-ea51-4450-848e-e7cff69238c7 |
| size | 1 |
| name | Share2 |
| share_type | c0086582-30a6-4060-b096-a42ec9d66b86 |
| created_at | 2015-09-25T06:25:50.000000 |
| export_location | 10.254.0.3:/shares/share-1dc2a471-3d47-...|
| share_proto | NFS |
| consistency_group_id | None |
| source_cgsnapshot_member_id | None |
| project_id | 20787a7ba11946adad976463b57d8a2f |
| metadata | {u'source': u'snapshot'} |
+-----------------------------+-------------------------------------------+Delete Share
If you do not need a share any more, you can delete it using manila delete share_name_or_ID command like:
$ manila delete Share2Note
If you specified the consistency group while creating a share, you should provide the --consistency-group parameter to delete the share:
$ manila delete ba52454e-2ea3-47fa-a683-3176a01295e6 --consistency-group \
ffee08d9-c86c-45e5-861e-175c731daca2Sometimes it appears that a share hangs in one of transitional states
(i.e.
creating, deleting, managing, unmanaging, extending, and shrinking).
In that case, to delete it, you need manila force-delete share_name_or_ID command and
administrative permissions to run it:
$ manila force-delete b6b0617c-ea51-4450-848e-e7cff69238c7Tip
For more details and additional information about other cases, features, API commands etc, see Share Management of “Shared File Systems” section of OpenStack Administrator Guide document.
Create Snapshots
The Shared File Systems service provides a mechanism of snapshots to
help users to restore their own data. To create a snapshot, use manila snapshot-create
command like:
$ manila snapshot-create Share1 --name Snapshot1 --description "Snapshot of Share1"
+-------------------+--------------------------------------+
| Property | Value |
+-------------------+--------------------------------------+
| status | creating |
| share_id | e7364bcc-3821-49bf-82d6-0c9f0276d4ce |
| description | Snapshot of Share1 |
| created_at | 2016-03-20T00:00:00.000000 |
| share_proto | NFS |
| provider_location | None |
| id | a96cf025-92d1-4012-abdd-bb0f29e5aa8f |
| size | 1 |
| share_size | 1 |
| name | Snapshot1 |
+-------------------+--------------------------------------+Then, if needed, update the name and description of the created snapshot:
$ manila snapshot-rename Snapshot1 Snapshot_1 --description "Snapshot of Share1. Updated."To make sure that the snapshot is available, run:
$ manila snapshot-show Snapshot1
+-------------------+--------------------------------------+
| Property | Value |
+-------------------+--------------------------------------+
| status | available |
| share_id | e7364bcc-3821-49bf-82d6-0c9f0276d4ce |
| description | Snapshot of Share1 |
| created_at | 2016-03-30T10:53:19.000000 |
| share_proto | NFS |
| provider_location | 3ca7a3b2-9f9f-46af-906f-6a565bf8ee37 |
| id | a96cf025-92d1-4012-abdd-bb0f29e5aa8f |
| size | 1 |
| share_size | 1 |
| name | Snapshot1 |
+-------------------+--------------------------------------+Tip
For more details and additional information on snapshots, see Share Snapshots of “Shared File Systems” section of “OpenStack Administrator Guide” document.
Create a Share Network
To control a share network, Shared File Systems service requires
interaction with Networking service to manage share servers on its own.
If the selected driver runs in a mode that requires such kind of
interaction, you need to specify the share network when a share is
created. For the information on share creation, see create_share earlier in this
chapter. Initially, check the existing share networks type list by:
$ manila share-network-list
+--------------------------------------+--------------+
| id | name |
+--------------------------------------+--------------+
+--------------------------------------+--------------+If share network list is empty or does not contain a required network, just create, for example, a share network with a private network and subnetwork.
$ manila share-network-create --neutron-net-id 5ed5a854-21dc-4ed3-870a-117b7064eb21 \
--neutron-subnet-id 74dcfb5a-b4d7-4855-86f5-a669729428dc --name my_share_net \
--description "My first share network"
+-------------------+--------------------------------------+
| Property | Value |
+-------------------+--------------------------------------+
| name | my_share_net |
| segmentation_id | None |
| created_at | 2015-09-24T12:06:32.602174 |
| neutron_subnet_id | 74dcfb5a-b4d7-4855-86f5-a669729428dc |
| updated_at | None |
| network_type | None |
| neutron_net_id | 5ed5a854-21dc-4ed3-870a-117b7064eb21 |
| ip_version | None |
| nova_net_id | None |
| cidr | None |
| project_id | 20787a7ba11946adad976463b57d8a2f |
| id | 5c3cbabb-f4da-465f-bc7f-fadbe047b85a |
| description | My first share network |
+-------------------+--------------------------------------+The segmentation_id, cidr,
ip_version, and network_type share network
attributes are automatically set to the values determined by the network
provider.
Then check if the network became created by requesting the networks list once again:
$ manila share-network-list
+--------------------------------------+--------------+
| id | name |
+--------------------------------------+--------------+
| 5c3cbabb-f4da-465f-bc7f-fadbe047b85a | my_share_net |
+--------------------------------------+--------------+Finally, to create a share that uses this share network, get to Create Share use case described earlier in this chapter.
Tip
See Share Networks of “Shared File Systems” section of OpenStack Administrator Guide document for more details.
Manage a Share Network
There is a pair of useful commands that help manipulate share networks. To start, check the network list:
$ manila share-network-list
+--------------------------------------+--------------+
| id | name |
+--------------------------------------+--------------+
| 5c3cbabb-f4da-465f-bc7f-fadbe047b85a | my_share_net |
+--------------------------------------+--------------+If you configured the back-end with
driver_handles_share_servers = True (with the share
servers) and had already some operations in the Shared File Systems
service, you can see manila_service_network in the neutron
list of networks. This network was created by the share driver for
internal usage.
$ openstack network list
+--------------+------------------------+------------------------------------+
| ID | Name | Subnets |
+--------------+------------------------+------------------------------------+
| 3b5a629a-e...| manila_service_network | 4f366100-50... 10.254.0.0/28 |
| bee7411d-d...| public | 884a6564-01... 2001:db8::/64 |
| | | e6da81fa-55... 172.24.4.0/24 |
| 5ed5a854-2...| private | 74dcfb5a-bd... 10.0.0.0/24 |
| | | cc297be2-51... fd7d:177d:a48b::/64 |
+--------------+------------------------+------------------------------------+You also can see detailed information about the share network
including network_type, segmentation_id fields:
$ openstack network show manila_service_network
+---------------------------+--------------------------------------+
| Field | Value |
+---------------------------+--------------------------------------+
| admin_state_up | True |
| availability_zone_hints | |
| availability_zones | nova |
| created_at | 2016-03-20T00:00:00 |
| description | |
| id | ef5282ab-dbf9-4d47-91d4-b0cc9b164567 |
| ipv4_address_scope | |
| ipv6_address_scope | |
| mtu | 1450 |
| name | manila_service_network |
| port_security_enabled | True |
| provider:network_type | vxlan |
| provider:physical_network | |
| provider:segmentation_id | 1047 |
| router:external | False |
| shared | False |
| status | ACTIVE |
| subnets | aba49c7d-c7eb-44b9-9c8f-f6112b05a2e0 |
| tags | |
| tenant_id | f121b3ee03804266af2959e56671b24a |
| updated_at | 2016-03-20T00:00:00 |
+---------------------------+--------------------------------------+You also can add and remove the security services to the share network.
Tip
For details, see subsection Security Services of “Shared File Systems” section of OpenStack Administrator Guide document.
Instances
Instances are the running virtual machines within an OpenStack cloud. This section deals with how to work with them and their underlying images, their network properties, and how they are represented in the database.
Starting Instances
To launch an instance, you need to select an image, a flavor, and a
name. The name needn't be unique, but your life will be simpler if it is
because many tools will use the name in place of the UUID so long as the
name is unique. You can start an instance from the dashboard from the
Launch Instance
button on the Instances page or by selecting the Launch action next to an
image or a snapshot on the Images page.
On the command line, do this:
$ openstack server create --flavor FLAVOR --image IMAGE NAMEThere are a number of optional items that can be specified. You should read the rest of this section before trying to start an instance, but this is the base command that later details are layered upon.
To delete instances from the dashboard, select the Delete Instance action
next to the instance on the Instances page.
Note
In releases prior to Mitaka, select the equivalent Terminate
instance action.
From the command line, do this:
$ openstack server delete INSTANCE_IDIt is important to note that powering off an instance does not terminate it in the OpenStack sense.
Instance Boot Failures
If an instance fails to start and immediately moves to an error state, there are a few different ways to track down what has gone wrong. Some of these can be done with normal user access, while others require access to your log server or compute nodes.
The simplest reasons for nodes to fail to launch are quota violations
or the scheduler being unable to find a suitable compute node on which
to run the instance. In these cases, the error is apparent when you run
a openstack server show on the faulted instance:
$ openstack server show test-instance
+--------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------+
| Field | Value |
+--------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------+
| OS-DCF:diskConfig | AUTO |
| OS-EXT-AZ:availability_zone | nova |
| OS-EXT-SRV-ATTR:host | None |
| OS-EXT-SRV-ATTR:hypervisor_hostname | None |
| OS-EXT-SRV-ATTR:instance_name | instance-0000000a |
| OS-EXT-STS:power_state | NOSTATE |
| OS-EXT-STS:task_state | None |
| OS-EXT-STS:vm_state | error |
| OS-SRV-USG:launched_at | None |
| OS-SRV-USG:terminated_at | None |
| accessIPv4 | |
| accessIPv6 | |
| addresses | |
| config_drive | |
| created | 2016-11-23T07:51:53Z |
| fault | {u'message': u'Build of instance 6ec42311-a121-4887-aece-48fb93a4a098 aborted: Failed to allocate the network(s), not rescheduling.', |
| | u'code': 500, u'details': u' File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 1779, in |
| | _do_build_and_run_instance\n filter_properties)\n File "/usr/lib/python2.7/site-packages/nova/compute/manager.py", line 1960, in |
| | _build_and_run_instance\n reason=msg)\n', u'created': u'2016-11-23T07:57:04Z'} |
| flavor | m1.tiny (1) |
| hostId | |
| id | 6ec42311-a121-4887-aece-48fb93a4a098 |
| image | cirros (9fef3b2d-c35d-4b61-bea8-09cc6dc41829) |
| key_name | None |
| name | test-instance |
| os-extended-volumes:volumes_attached | [] |
| project_id | 5669caad86a04256994cdf755df4d3c1 |
| properties | |
| status | ERROR |
| updated | 2016-11-23T07:57:04Z |
| user_id | c36cec73b0e44876a4478b1e6cd749bb |
+--------------------------------------+---------------------------------------------------------------------------------------------------------------------------------------+In this case, looking at the fault message shows
NoValidHost, indicating that the scheduler was unable to
match the instance requirements.
If openstack server show does not sufficiently
explain the failure, searching for the instance UUID in the
nova-compute.log on the compute node it was scheduled on or
the nova-scheduler.log on your scheduler hosts is a good
place to start looking for lower-level problems.
Using openstack server show as an admin user will show
the compute node the instance was scheduled on as hostId.
If the instance failed during scheduling, this field is blank.
Using Instance-Specific Data
There are two main types of instance-specific data: metadata and user data.
Instance metadata
For Compute, instance metadata is a collection of key-value pairs associated with an instance. Compute reads and writes to these key-value pairs any time during the instance lifetime, from inside and outside the instance, when the end user uses the Compute API to do so. However, you cannot query the instance-associated key-value pairs with the metadata service that is compatible with the Amazon EC2 metadata service.
For an example of instance metadata, users can generate and register
SSH keys using the openstack keypair create command:
$ openstack keypair create mykey > mykey.pemThis creates a key named mykey, which you can associate
with instances. The file mykey.pem is the private key,
which should be saved to a secure location because it allows root access
to instances the mykey key is associated with.
Use this command to register an existing key with OpenStack:
$ openstack keypair create --public-key mykey.pub mykeyNote
You must have the matching private key to access instances associated with this key.
To associate a key with an instance on boot, add --key-name mykey to your
command line. For example:
$ openstack server create --image ubuntu-cloudimage --flavor 2 \
--key-name mykey myimageWhen booting a server, you can also add arbitrary metadata so that
you can more easily identify it among other running instances. Use the
--property option
with a key-value pair, where you can make up the string for both the key
and the value. For example, you could add a description and also the
creator of the server:
$ openstack server create --image=test-image --flavor=1 \
--property description='Small test image' smallimageWhen viewing the server information, you can see the metadata included on the metadata line:
$ openstack server show smallimage
+--------------------------------------+----------------------------------------------------------+
| Field | Value |
+--------------------------------------+----------------------------------------------------------+
| OS-DCF:diskConfig | MANUAL |
| OS-EXT-AZ:availability_zone | nova |
| OS-EXT-SRV-ATTR:host | rdo-newton.novalocal |
| OS-EXT-SRV-ATTR:hypervisor_hostname | rdo-newton.novalocal |
| OS-EXT-SRV-ATTR:instance_name | instance-00000002 |
| OS-EXT-STS:power_state | Running |
| OS-EXT-STS:task_state | None |
| OS-EXT-STS:vm_state | active |
| OS-SRV-USG:launched_at | 2016-12-07T11:20:08.000000 |
| OS-SRV-USG:terminated_at | None |
| accessIPv4 | |
| accessIPv6 | |
| addresses | public=172.24.4.227 |
| config_drive | |
| created | 2016-12-07T11:17:44Z |
| flavor | m1.tiny (1) |
| hostId | aca973d5b7981faaf8c713a0130713bbc1e64151be65c8dfb53039f7 |
| id | 4f7c6b2c-f27e-4ccd-a606-6bfc9d7c0d91 |
| image | cirros (01bcb649-45d7-4e3d-8a58-1fcc87816907) |
| key_name | None |
| name | smallimage |
| os-extended-volumes:volumes_attached | [] |
| progress | 0 |
| project_id | 2daf82a578e9437cab396c888ff0ca57 |
| properties | description='Small test image' |
| security_groups | [{u'name': u'default'}] |
| status | ACTIVE |
| updated | 2016-12-07T11:20:08Z |
| user_id | 8cbea24666ae49bbb8c1641f9b12d2d2 |
+--------------------------------------+----------------------------------------------------------+Instance user data
The user-data key is a special key in the metadata
service that holds a file that cloud-aware applications within the guest
instance can access. For example, cloudinit is an
open source package from Ubuntu, but available in most distributions,
that handles early initialization of a cloud instance that makes use of
this user data.
This user data can be put in a file on your local system and then
passed in at instance creation with the flag --user-data
<user-data-file>.
For example
$ openstack server create --image ubuntu-cloudimage --flavor 1 \
--user-data mydata.file mydatainstanceTo understand the difference between user data and metadata, realize that user data is created before an instance is started. User data is accessible from within the instance when it is running. User data can be used to store configuration, a script, or anything the tenant wants.
File injection
Arbitrary local files can also be placed into the instance file
system at creation time by using the --file <dst-path=src-path>
option. You may store up to five files.
For example, let's say you have a special
authorized_keys file named special_authorized_keysfile that
for some reason you want to put on the instance instead of using the
regular SSH key injection. In this case, you can use the following
command:
$ openstack server create --image ubuntu-cloudimage --flavor 1 \
--file /root/.ssh/authorized_keys=special_authorized_keysfile \
authkeyinstanceAssociating Security Groups
Security groups, as discussed earlier, are typically required to allow network traffic to an instance, unless the default security group for a project has been modified to be more permissive.
Adding security groups is typically done on instance boot. When
launching from the dashboard, you do this on the Access & Security
tab of the Launch Instance dialog. When launching from the
command line, append --security-groups with a
comma-separated list of security groups.
It is also possible to add and remove security groups when an instance is running. Currently this is only available through the command-line tools. Here is an example:
$ openstack server add security group <server> <securitygroup>$ openstack server remove security group <server> <securitygroup>Floating IPs
Where floating IPs are configured in a deployment, each project will
have a limited number of floating IPs controlled by a quota. However,
these need to be allocated to the project from the central pool prior to
their use—usually by the administrator of the project. To allocate a
floating IP to a project, use the Allocate IP To Project button on the Floating IPs tab of the
Access & Security page of the dashboard. The
command line can also be used:
$ openstack floating ip create NETWORKOnce allocated, a floating IP can be assigned to running instances
from the dashboard either by selecting Associate from the actions drop-down next to the
IP on the Floating IPs tab of the Access & Security
page or by making this selection next to the instance you want to
associate it with on the Instances page. The inverse action, Dissociate
Floating IP, is available from the Floating IPs tab of the Access & Security
page and from the Instances page.
To associate or disassociate a floating IP with a server from the command line, use the following commands:
$ openstack server add floating ip SERVER IP_ADDRESS$ openstack server remove floating ip SERVER IP_ADDRESSAttaching Block Storage
You can attach block storage to instances from the dashboard on the
Volumes page.
Click the Manage Attachments action next to the volume you
want to attach.
To perform this action from command line, run the following command:
$ nova volume-attach <server> <volume> <device>You can also specify block deviceblock device mapping at instance boot time through the nova command-line client with this option set:
--block-device-mapping <dev-name=mapping>The block device mapping format is
<dev-name>=<id>:<type>:<size(GB)>:<delete-on-terminate>,
where:
- dev-name
-
A device name where the volume is attached in the system at
/dev/dev_name - id
-
The ID of the volume to boot from, as shown in the output of
nova volume-list - type
-
Either
snap, which means that the volume was created from a snapshot, or anything other thansnap(a blank string is valid). In the preceding example, the volume was not created from a snapshot, so we leave this field blank in our following example. - size (GB)
-
The size of the volume in gigabytes. It is safe to leave this blank and have the Compute Service infer the size.
- delete-on-terminate
-
A boolean to indicate whether the volume should be deleted when the instance is terminated. True can be specified as
Trueor1. False can be specified asFalseor0.
The following command will boot a new instance and attach a volume at
the same time. The volume of ID 13 will be attached as
/dev/vdc. It is not a snapshot, does not specify a size,
and will not be deleted when the instance is terminated:
$ openstack server create --image 4042220e-4f5e-4398-9054-39fbd75a5dd7 \
--flavor 2 --key-name mykey --block-device-mapping vdc=13:::0 \
boot-with-vol-testIf you have previously prepared block storage with a bootable file
system image, it is even possible to boot from persistent block storage.
The following command boots an image from the specified volume. It is
similar to the previous command, but the image is omitted and the volume
is now attached as /dev/vda:
$ openstck server create --flavor 2 --key-name mykey \
--block-device-mapping vda=13:::0 boot-from-vol-testRead more detailed instructions for launching an instance from a bootable volume in the OpenStack End User Guide.
To boot normally from an image and attach block storage, map to a device other than vda. You can find instructions for launching an instance and attaching a volume to the instance and for copying the image to the attached volume in the OpenStack End User Guide.
Taking Snapshots
The OpenStack snapshot mechanism allows you to create new images from running instances. This is very convenient for upgrading base images or for taking a published image and customizing it for local use. To snapshot a running instance to an image using the CLI, do this:
$ openstack image create <image name> --volume <volume name of instance>The dashboard interface for snapshots can be confusing because the
snapshots and images are displayed in the Images page. However, an instance snapshot
is an image. The only difference between an image that you
upload directly to the Image Service and an image that you create by
snapshot is that an image created by snapshot has additional properties
in the glance database. These properties are found in the
image_properties table and include:
| Name | Value |
|---|---|
image_type |
snapshot |
instance_uuid |
<uuid of instance that was snapshotted> |
base_image_ref |
<uuid of original image of instance that was snapshotted> |
image_location |
snapshot |
Live Snapshots
Live snapshots is a feature that allows users to snapshot the running virtual machines without pausing them. These snapshots are simply disk-only snapshots. Snapshotting an instance can now be performed with no downtime (assuming QEMU 1.3+ and libvirt 1.0+ are used).
Note
If you use libvirt version 1.2.2, you may experience
intermittent problems with live snapshot creation.
To effectively disable the libvirt live snapshotting, until the problem is resolved, add the below setting to nova.conf.
[workarounds]
disable_libvirt_livesnapshot = TrueEnsuring Snapshots of Linux Guests Are Consistent
The following section is from Sébastien Han's “OpenStack: Perform Consistent Snapshots” blog entry.
A snapshot captures the state of the file system, but not the state of the memory. Therefore, to ensure your snapshot contains the data that you want, before your snapshot you need to ensure that:
- Running programs have written their contents to disk
- The file system does not have any "dirty" buffers: where programs have issued the command to write to disk, but the operating system has not yet done the write
To ensure that important services have written their contents to disk (such as databases), we recommend that you read the documentation for those applications to determine what commands to issue to have them sync their contents to disk. If you are unsure how to do this, the safest approach is to simply stop these running services normally.
To deal with the "dirty" buffer issue, we recommend using the sync command before snapshotting:
# syncRunning sync writes dirty buffers (buffered blocks that
have been modified but not written yet to the disk block) to disk.
Just running sync is not enough to ensure that the file
system is consistent. We recommend that you use the
fsfreeze tool, which halts new access to the file system,
and create a stable image on disk that is suitable for snapshotting. The
fsfreeze tool supports several file systems, including
ext3, ext4, and XFS. If your virtual machine instance is running on
Ubuntu, install the util-linux package to get fsfreeze:
Note
In the very common case where the underlying snapshot is done via LVM, the filesystem freeze is automatically handled by LVM.
# apt-get install util-linuxIf your operating system doesn't have a version of
fsfreeze available, you can use xfs_freeze
instead, which is available on Ubuntu in the xfsprogs package. Despite
the "xfs" in the name, xfs_freeze also works on ext3 and ext4 if you are
using a Linux kernel version 2.6.29 or greater, since it works at the
virtual file system (VFS) level starting at 2.6.29. The xfs_freeze
version supports the same command-line arguments as
fsfreeze.
Consider the example where you want to take a snapshot of a
persistent block storage volume, detected by the guest operating system
as /dev/vdb and mounted on /mnt. The fsfreeze
command accepts two arguments:
- -f
-
Freeze the system
- -u
-
Thaw (unfreeze) the system
To freeze the volume in preparation for snapshotting, you would do the following, as root, inside the instance:
# fsfreeze -f /mntYou must mount the file system before you run the fsfreeze command.
When the fsfreeze -f command is issued, all ongoing
transactions in the file system are allowed to complete, new write
system calls are halted, and other calls that modify the file system are
halted. Most importantly, all dirty data, metadata, and log information
are written to disk.
Once the volume has been frozen, do not attempt to read from or write to the volume, as these operations hang. The operating system stops every I/O operation and any I/O attempts are delayed until the file system has been unfrozen.
Once you have issued the fsfreeze command, it is safe to perform the
snapshot. For example, if the volume of your instance was named
mon-volume and you wanted to snapshot it to an image named
mon-snapshot, you could now run the following:
$ openstack image create mon-snapshot --volume mon-volumeWhen the snapshot is done, you can thaw the file system with the following command, as root, inside of the instance:
# fsfreeze -u /mntIf you want to back up the root file system, you can't simply run the preceding command because it will freeze the prompt. Instead, run the following one-liner, as root, inside the instance:
# fsfreeze -f / && read x; fsfreeze -u /After this command it is common practice to call openstack image create
from your workstation, and once done press enter in your instance shell
to unfreeze it. Obviously you could automate this, but at least it will
let you properly synchronize.
Ensuring Snapshots of Windows Guests Are Consistent
Obtaining consistent snapshots of Windows VMs is conceptually similar to obtaining consistent snapshots of Linux VMs, although it requires additional utilities to coordinate with a Windows-only subsystem designed to facilitate consistent backups.
Windows XP and later releases include a Volume Shadow Copy Service (VSS) which provides a framework so that compliant applications can be consistently backed up on a live filesystem. To use this framework, a VSS requestor is run that signals to the VSS service that a consistent backup is needed. The VSS service notifies compliant applications (called VSS writers) to quiesce their data activity. The VSS service then tells the copy provider to create a snapshot. Once the snapshot has been made, the VSS service unfreezes VSS writers and normal I/O activity resumes.
QEMU provides a guest agent that can be run in guests running on KVM hypervisors. This guest agent, on Windows VMs, coordinates with the Windows VSS service to facilitate a workflow which ensures consistent snapshots. This feature requires at least QEMU 1.7. The relevant guest agent commands are:
- guest-file-flush
-
Write out "dirty" buffers to disk, similar to the Linux
syncoperation. - guest-fsfreeze
-
Suspend I/O to the disks, similar to the Linux
fsfreeze -foperation. - guest-fsfreeze-thaw
-
Resume I/O to the disks, similar to the Linux
fsfreeze -uoperation.
To obtain snapshots of a Windows VM these commands can be scripted in sequence: flush the filesystems, freeze the filesystems, snapshot the filesystems, then unfreeze the filesystems. As with scripting similar workflows against Linux VMs, care must be used when writing such a script to ensure error handling is thorough and filesystems will not be left in a frozen state.
Instances in the Database
While instance information is stored in a number of database tables, the table you most likely need to look at in relation to user instances is the instances table.
The instances table carries most of the information related to both running and deleted instances. It has a bewildering array of fields; for an exhaustive list, look at the database. These are the most useful fields for operators looking to form queries:
- The
deletedfield is set to1if the instance has been deleted andNULLif it has not been deleted. This field is important for excluding deleted instances from your queries. - The
uuidfield is the UUID of the instance and is used throughout other tables in the database as a foreign key. This ID is also reported in logs, the dashboard, and command-line tools to uniquely identify an instance. - A collection of foreign keys are available to find relations to the
instance. The most useful of these —
user_idandproject_idare the UUIDs of the user who launched the instance and the project it was launched in. - The
hostfield tells which compute node is hosting the instance. - The
hostnamefield holds the name of the instance when it is launched. The display-name is initially the same as hostname but can be reset using the nova rename command.
A number of time-related fields are useful for tracking when state changes happened on an instance:
created_atupdated_atdeleted_atscheduled_atlaunched_atterminated_at
Good Luck!
This section was intended as a brief introduction to some of the most useful of many OpenStack commands. For an exhaustive list, please refer to the OpenStack Administrator Guide. We hope your users remain happy and recognize your hard work! (For more hard work, turn the page to the next chapter, where we discuss the system-facing operations: maintenance, failures and debugging.)