Update README for Ceph EC pools
This updates the README for erasure coded Ceph pools for the case of Ceph-backed Nova images. The new text should be as similar as possible for all the charms that support configuration options for EC pools. See the below review for the first of these charms whose README has been updated. https://review.opendev.org/#/c/749824/ Add basic README template sections (Actions, Bugs, Configuration). Standardise Network spaces section. Demystify the ceph-access endpoint relation. Change-Id: I9c7426dc8a8a53f412e7222e125f9746cf2ae804
This commit is contained in:
Peter Matulis
parent
b398e40165
commit
d381f25593
168
README.md
168
README.md
|
|
@ -1,11 +1,9 @@
|
|||
Overview
|
||||
========
|
||||
# Overview
|
||||
|
||||
This charm provides Nova Compute, the OpenStack compute service. Its target
|
||||
platform is Ubuntu (preferably LTS) + OpenStack.
|
||||
|
||||
Usage
|
||||
=====
|
||||
# Usage
|
||||
|
||||
The following interfaces are provided:
|
||||
|
||||
|
|
@ -15,37 +13,112 @@ The following interfaces are provided:
|
|||
|
||||
- nrpe-external-master - Used to generate Nagios checks.
|
||||
|
||||
Database
|
||||
========
|
||||
## Configuration
|
||||
|
||||
This section covers common and/or important configuration options. See file
|
||||
`config.yaml` for the full list of options, along with their descriptions and
|
||||
default values. See the [Juju documentation][juju-docs-config-apps] for details
|
||||
on configuring applications.
|
||||
|
||||
#### `openstack-origin`
|
||||
|
||||
The `openstack-origin` option states the software sources. A common value is an
|
||||
OpenStack UCA release (e.g. 'cloud:xenial-queens' or 'cloud:bionic-ussuri').
|
||||
See [Ubuntu Cloud Archive][wiki-uca]. The underlying host's existing apt
|
||||
sources will be used if this option is not specified (this behaviour can be
|
||||
explicitly chosen by using the value of 'distro').
|
||||
|
||||
#### `pool-type`
|
||||
|
||||
The `pool-type` option dictates the Ceph storage pool type. See sections 'Ceph
|
||||
pool type' and 'RBD Nova images' for more information.
|
||||
|
||||
## Ceph pool type
|
||||
|
||||
Ceph storage pools can be configured to ensure data resiliency either through
|
||||
replication or by erasure coding. This charm supports both types via the
|
||||
`pool-type` configuration option, which can take on the values of 'replicated'
|
||||
and 'erasure-coded'. The default value is 'replicated'.
|
||||
|
||||
For this charm, the pool type will be associated with Nova-managed images.
|
||||
|
||||
> **Note**: Erasure-coded pools are supported starting with Ceph Luminous.
|
||||
|
||||
### Replicated pools
|
||||
|
||||
Replicated pools use a simple replication strategy in which each written object
|
||||
is copied, in full, to multiple OSDs within the cluster.
|
||||
|
||||
The `ceph-osd-replication-count` option sets the replica count for any object
|
||||
stored within the 'nova' rbd pool. Increasing this value increases data
|
||||
resilience at the cost of consuming more real storage in the Ceph cluster. The
|
||||
default value is '3'.
|
||||
|
||||
> **Important**: The `ceph-osd-replication-count` option must be set prior to
|
||||
adding the relation to the ceph-mon application. Otherwise, the pool's
|
||||
configuration will need to be set by interfacing with the cluster directly.
|
||||
|
||||
### Erasure coded pools
|
||||
|
||||
Erasure coded pools use a technique that allows for the same resiliency as
|
||||
replicated pools, yet reduces the amount of space required. Written data is
|
||||
split into data chunks and error correction chunks, which are both distributed
|
||||
throughout the cluster.
|
||||
|
||||
> **Note**: Erasure coded pools require more memory and CPU cycles than
|
||||
replicated pools do.
|
||||
|
||||
When using erasure coding two pools will be created: a replicated pool (for
|
||||
storing RBD metadata) and an erasure coded pool (for storing the data written
|
||||
into the RBD). The `ceph-osd-replication-count` configuration option only
|
||||
applies to the metadata (replicated) pool.
|
||||
|
||||
Erasure coded pools can be configured via options whose names begin with the
|
||||
`ec-` prefix.
|
||||
|
||||
> **Important**: It is strongly recommended to tailor the `ec-profile-k` and
|
||||
`ec-profile-m` options to the needs of the given environment. These latter
|
||||
options have default values of '1' and '2' respectively, which result in the
|
||||
same space requirements as those of a replicated pool.
|
||||
|
||||
See [Ceph Erasure Coding][cdg-ceph-erasure-coding] in the [OpenStack Charms
|
||||
Deployment Guide][cdg] for more information.
|
||||
|
||||
## Database
|
||||
|
||||
Nova compute only requires database access if using nova-network. If using
|
||||
Neutron, no direct database access is required and the shared-db relation need
|
||||
not be added. The nova-network feature is not available in Ussuri and later,
|
||||
and so this interface produces a warning if added.
|
||||
|
||||
Networking
|
||||
==========
|
||||
## Networking
|
||||
|
||||
This charm support nova-network (legacy) and Neutron networking.
|
||||
|
||||
Storage
|
||||
=======
|
||||
## Ceph backed storage
|
||||
|
||||
This charm supports a number of different storage backends depending on
|
||||
your hypervisor type and storage relations.
|
||||
|
||||
In order to have cinder ceph rbd support for OpenStack Ocata and newer
|
||||
releases, ceph-access relation must be added to cinder-ceph to allow
|
||||
nova-compute units to communicate with multiple ceph backends using
|
||||
different cephx keys and user names.
|
||||
### RBD Nova images
|
||||
|
||||
$ juju add-relation nova-compute cinder-ceph
|
||||
To make Ceph the storage backend for Nova non-bootable disk images
|
||||
configuration option `libvirt-image-backend` must be set to 'rbd'. The below
|
||||
relation is also required:
|
||||
|
||||
See LP Bug [#1671422](https://bugs.launchpad.net/charm-cinder-ceph/+bug/1671422)
|
||||
for more information.
|
||||
juju add-relation nova-compute:ceph ceph-mon:client
|
||||
|
||||
Availability Zones
|
||||
==================
|
||||
### RBD Cinder volumes
|
||||
|
||||
Starting with OpenStack Ocata, in order to maintain Cinder RBD support the
|
||||
below relation is required:
|
||||
|
||||
juju add-relation nova-compute:ceph-access cinder-ceph:ceph-access
|
||||
|
||||
This allows Nova to communicate with multiple Ceph backends using different
|
||||
cephx keys and user names.
|
||||
|
||||
## Availability Zones
|
||||
|
||||
There are two options to provide default_availability_zone config
|
||||
for nova nodes:
|
||||
|
|
@ -75,8 +148,7 @@ instance creation.
|
|||
These options also affect the AZ propagated down to networking
|
||||
subordinates which is useful for AZ-aware Neutron agent scheduling.
|
||||
|
||||
NFV support
|
||||
===========
|
||||
## NFV support
|
||||
|
||||
This charm (in conjunction with the nova-cloud-controller and neutron-api charms)
|
||||
supports use of nova-compute nodes configured for use in Telco NFV deployments;
|
||||
|
|
@ -160,20 +232,54 @@ The [OpenStack advanced networking documentation](http://docs.openstack.org/mita
|
|||
provides further details on whitelist configuration and how to create instances
|
||||
with Neutron ports wired to SR-IOV devices.
|
||||
|
||||
Network Spaces
|
||||
==============
|
||||
## Network spaces
|
||||
|
||||
This charm supports use of network spaces by binding relation endpoints.
|
||||
This charm supports the use of Juju [network spaces][juju-docs-spaces] (Juju
|
||||
`v.2.0`). This feature optionally allows specific types of the application's
|
||||
network traffic to be bound to subnets that the underlying hardware is
|
||||
connected to.
|
||||
|
||||
> **Note**: Spaces must be configured in the backing cloud prior to deployment.
|
||||
|
||||
In addition this charm declares two extra-bindings:
|
||||
|
||||
- **internal**: this binding is used to determine the network space
|
||||
to use for console access to instances.
|
||||
* `internal`: used to determine the network space to use for console access to
|
||||
instances.
|
||||
|
||||
- **migration**: this binding is used to determine which network space
|
||||
should be used for live and cold migrations between hypervisors.
|
||||
* `migration`: used to determine which network space should be used for live
|
||||
and cold migrations between hypervisors.
|
||||
|
||||
Note that the nova-cloud-controller application must have bindings to the
|
||||
same network spaces used for both 'internal' and 'migration' extra bindings.
|
||||
Note that the nova-cloud-controller application must have bindings to the same
|
||||
network spaces used for both 'internal' and 'migration' extra bindings.
|
||||
|
||||
See the [Juju documentation](https://juju.is/docs/spaces) for more information on using network spaces.
|
||||
## Actions
|
||||
|
||||
This section lists Juju [actions][juju-docs-actions] supported by the charm.
|
||||
Actions allow specific operations to be performed on a per-unit basis. To
|
||||
display action descriptions run `juju actions ceph-mon`. If the charm is not
|
||||
deployed then see file `actions.yaml`.
|
||||
|
||||
* `openstack-upgrade`
|
||||
* `pause`
|
||||
* `resume`
|
||||
* `hugepagereport`
|
||||
* `security-checklist`
|
||||
|
||||
# Bugs
|
||||
|
||||
Please report bugs on [Launchpad][lp-bugs-charm-nova-compute].
|
||||
|
||||
For general charm questions refer to the OpenStack [Charm Guide][cg].
|
||||
|
||||
<!-- LINKS -->
|
||||
|
||||
[cg]: https://docs.openstack.org/charm-guide
|
||||
[cdg]: https://docs.openstack.org/project-deploy-guide/charm-deployment-guide
|
||||
[juju-docs-actions]: https://jaas.ai/docs/actions
|
||||
[juju-docs-spaces]: https://juju.is/docs/spaces
|
||||
[juju-docs-config-apps]: https://juju.is/docs/configuring-applications
|
||||
[lp-bugs-charm-nova-compute]: https://bugs.launchpad.net/charm-nova-compute/+filebug
|
||||
[cdg-install-openstack]: https://docs.openstack.org/project-deploy-guide/charm-deployment-guide/latest/install-openstack.html
|
||||
[cloud-archive-ceph]: https://wiki.ubuntu.com/OpenStack/CloudArchive#Ceph_and_the_UCA
|
||||
[wiki-uca]: https://wiki.ubuntu.com/OpenStack/CloudArchive
|
||||
[cdg-ceph-erasure-coding]: https://docs.openstack.org/project-deploy-guide/charm-deployment-guide/latest/app-erasure-coding.html
|
||||
|
|
|
|||
Loading…
Reference in New Issue