openstack-manuals/doc/admin-guide-cloud/compute/section_compute-system-admin.xml
Lars Kellogg-Stedman 3a366a9246 minor update regarding serial console reqs
I missed the chance to comment on
https://review.openstack.org/#/c/149533/.  I wanted to suggest this edit
to emphasize that one does not require *python* websocket in particular
to access the serial console, but that any websocket client library
would be appropriate.

Change-Id: Iff82deac5adce5811f884ed14daa7c586fed2dd0
2015-02-06 09:55:08 -05:00

573 lines
36 KiB
XML

<?xml version="1.0" encoding="UTF-8"?>
<section xmlns="http://docbook.org/ns/docbook" xmlns:xi="http://www.w3.org/2001/XInclude"
xmlns:xlink="http://www.w3.org/1999/xlink" version="5.0" xml:id="section_compute-system-admin">
<title>System administration</title>
<para>By understanding how the different installed nodes interact with each other, you can
administer the Compute installation. Compute offers many ways to install using multiple
servers but the general idea is that you can have multiple compute nodes that control the
virtual servers and a cloud controller node that contains the remaining Compute
services.</para>
<para>The Compute cloud works through the interaction of a series of daemon processes named
<systemitem>nova-*</systemitem> that reside persistently on the host machine or
machines. These binaries can all run on the same machine or be spread out on multiple boxes
in a large deployment. The responsibilities of services and drivers are:</para>
<para>
<itemizedlist>
<listitem>
<para>Services:</para>
<itemizedlist>
<listitem>
<para><systemitem class="service">nova-api</systemitem>. Receives XML
requests and sends them to the rest of the system. It is a WSGI app that
routes and authenticate requests. It supports the EC2 and OpenStack
APIs. There is a <filename>nova-api.conf</filename> file created when
you install Compute.</para>
</listitem>
<listitem>
<para><systemitem>nova-cert</systemitem>. Provides the certificate
manager.</para>
</listitem>
<listitem>
<para><systemitem class="service">nova-compute</systemitem>. Responsible for
managing virtual machines. It loads a Service object, which exposes the
public methods on ComputeManager through Remote Procedure Call
(RPC).</para>
</listitem>
<listitem>
<para><systemitem>nova-conductor</systemitem>. Provides database-access
support for Compute nodes (thereby reducing security risks).</para>
</listitem>
<listitem>
<para><systemitem>nova-consoleauth</systemitem>. Handles console
authentication.</para>
</listitem>
<listitem>
<para><systemitem class="service">nova-objectstore</systemitem>: The
<systemitem class="service">nova-objectstore</systemitem> service is
an ultra simple file-based storage system for images that replicates
most of the S3 API. It can be replaced with OpenStack Image Service and
a simple image manager or use OpenStack Object Storage as the virtual
machine image storage facility. It must reside on the same node as
<systemitem class="service">nova-compute</systemitem>.</para>
</listitem>
<listitem>
<para><systemitem class="service">nova-network</systemitem>. Responsible for
managing floating and fixed IPs, DHCP, bridging and VLANs. It loads a
Service object which exposes the public methods on one of the subclasses
of NetworkManager. Different networking strategies are available to the
service by changing the network_manager configuration option to
FlatManager, FlatDHCPManager, or VlanManager (default is VLAN if no
other is specified).</para>
</listitem>
<listitem>
<para><systemitem>nova-scheduler</systemitem>. Dispatches requests for new
virtual machines to the correct node.</para>
</listitem>
<listitem>
<para><systemitem>nova-novncproxy</systemitem>. Provides a VNC proxy for
browsers (enabling VNC consoles to access virtual machines).</para>
</listitem>
</itemizedlist>
</listitem>
<listitem>
<para>Some services have drivers that change how the service implements the core of
its functionality. For example, the <systemitem>nova-compute</systemitem>
service supports drivers that let you choose with which hypervisor type it will
talk. <systemitem>nova-network</systemitem> and
<systemitem>nova-scheduler</systemitem> also have drivers.</para>
</listitem>
</itemizedlist>
</para>
<section xml:id="section_manage-compute-users">
<title>Manage Compute users</title>
<para>Access to the Euca2ools (ec2) API is controlled by an access and secret key. The
user's access key needs to be included in the request, and the request must be signed
with the secret key. Upon receipt of API requests, Compute verifies the signature and
runs commands on behalf of the user.</para>
<para>To begin using Compute, you must create a user with the Identity Service.</para>
</section>
<xi:include href="../../common/section_cli_nova_volumes.xml"/>
<xi:include href="../../common/section_cli_nova_customize_flavors.xml"/>
<xi:include href="section_compute_config-firewalls.xml"/>
<section xml:id="admin-password-injection">
<?dbhtml stop-chunking?>
<title>Inject administrator password</title>
<para>You can configure Compute to generate a random administrator (root) password and
inject that password into the instance. If this feature is enabled, a user can
<command>ssh</command> to an instance without an <command>ssh</command> keypair. The
random password appears in the output of the <command>nova boot</command> command. You
can also view and set the <literal>admin</literal> password from the dashboard.</para>
<simplesect>
<title>Dashboard</title>
<para>The dashboard is configured by default to display the <literal>admin</literal>
password and allow the user to modify it.</para>
<para>If you do not want to support password injection, we recommend disabling the
password fields by editing your Dashboard <filename>local_settings</filename> file
(file location will vary by Linux distribution, on Fedora/RHEL/CentOS: <filename>
/etc/openstack-dashboard/local_settings</filename>, on Ubuntu and Debian:
<filename>/etc/openstack-dashboard/local_settings.py</filename> and on openSUSE
and SUSE Linux Enterprise Server:
<filename>/srv/www/openstack-dashboard/openstack_dashboard/local/local_settings.py</filename>)
<programlisting language="ini">OPENSTACK_HYPERVISOR_FEATURE = {
...
'can_set_password': False,
}</programlisting></para>
</simplesect>
<simplesect>
<title>Libvirt-based hypervisors (KVM, QEMU, LXC)</title>
<para>For hypervisors such as KVM that use the libvirt backend, <literal>admin</literal>
password injection is disabled by default. To enable it, set the following option in
<filename>/etc/nova/nova.conf</filename>:</para>
<para>
<programlisting language="ini">[libvirt]
inject_password=true</programlisting>
</para>
<para>When enabled, Compute will modify the password of the root account by editing the
<filename>/etc/shadow</filename> file inside of the virtual machine
instance.</para>
<note>
<para>Users can only ssh to the instance by using the admin password if:</para>
<itemizedlist>
<listitem>
<para>The virtual machine image is a Linux distribution</para>
</listitem>
<listitem>
<para>The virtual machine has been configured to allow users to
<command>ssh</command> as the root user. This is not the case for
<link xlink:href="http://cloud-images.ubuntu.com/">Ubuntu cloud
images</link>, which disallow <command>ssh</command> to the root
account by default.</para>
</listitem>
</itemizedlist>
</note>
</simplesect>
<simplesect>
<title>XenAPI (XenServer/XCP)</title>
<para>Compute uses the XenAPI agent to inject passwords into guests when using the
XenAPI hypervisor backend. The virtual-machine image must be configured with the
agent for password injection to work.</para>
</simplesect>
<simplesect>
<title>Windows images (all hypervisors)</title>
<para>To support the <literal>admin</literal> password for Windows virtual machines, you
must configure the Windows image to retrieve the <literal>admin</literal> password
on boot by installing an agent such as <link
xlink:href="https://github.com/cloudbase/cloudbase-init"
>cloudbase-init</link>.</para>
</simplesect>
</section>
<section xml:id="section_manage-the-cloud">
<title>Manage the cloud</title>
<para>A system administrator can use the <command>nova</command> client and the
<command>Euca2ools</command> commands to manage the cloud.</para>
<para>Both nova client and euca2ools can be used by all users, though specific commands
might be restricted by Role Based Access Control in the Identity Service.</para>
<procedure>
<title>To use the nova client</title>
<step>
<para>Installing the <package>python-novaclient</package> package gives you a
<code>nova</code> shell command that enables Compute API interactions from
the command line. Install the client, and then provide your user name and
password (typically set as environment variables for convenience), and then you
have the ability to send commands to your cloud on the command line.</para>
<para>To install <package>python-novaclient</package>, download the tarball from
<link
xlink:href="http://pypi.python.org/pypi/python-novaclient/#downloads"
>http://pypi.python.org/pypi/python-novaclient/#downloads</link> and
then install it in your favorite python environment.</para>
<screen><prompt>$</prompt> <userinput>curl -O http://pypi.python.org/packages/source/p/python-novaclient/python-novaclient-2.6.3.tar.gz</userinput>
<prompt>$</prompt> <userinput>tar -zxvf python-novaclient-2.6.3.tar.gz</userinput>
<prompt>$</prompt> <userinput>cd python-novaclient-2.6.3</userinput></screen>
<para>As <systemitem class="username">root</systemitem>, run:</para>
<screen><prompt>#</prompt> <userinput>python setup.py install</userinput></screen>
</step>
<step>
<para>Confirm the installation:</para>
<screen><prompt>$</prompt> <userinput>nova help</userinput>
<computeroutput>usage: nova [--version] [--debug] [--os-cache] [--timings]
[--timeout <replaceable>SECONDS</replaceable>] [--os-username <replaceable>AUTH_USER_NAME</replaceable>]
[--os-password <replaceable>AUTH_PASSWORD</replaceable>]
[--os-tenant-name <replaceable>AUTH_TENANT_NAME</replaceable>]
[--os-tenant-id <replaceable>AUTH_TENANT_ID</replaceable>] [--os-auth-url <replaceable>AUTH_URL</replaceable>]
[--os-region-name <replaceable>REGION_NAME</replaceable>] [--os-auth-system <replaceable>AUTH_SYSTEM</replaceable>]
[--service-type <replaceable>SERVICE_TYPE</replaceable>] [--service-name <replaceable>SERVICE_NAME</replaceable>]
[--volume-service-name <replaceable>VOLUME_SERVICE_NAME</replaceable>]
[--endpoint-type <replaceable>ENDPOINT_TYPE</replaceable>]
[--os-compute-api-version <replaceable>COMPUTE_API_VERSION</replaceable>]
[--os-cacert <replaceable>CA_CERTIFICATE</replaceable>] [--insecure]
[--bypass-url <replaceable>BYPASS_URL</replaceable>]
<replaceable>SUBCOMMAND</replaceable> ...</computeroutput></screen>
<note>
<para>This command returns a list of <command>nova</command> commands and
parameters. To obtain help for a subcommand, run:</para>
<screen><prompt>$</prompt> <userinput>nova help <replaceable>SUBCOMMAND</replaceable></userinput></screen>
<para>You can also refer to the <link
xlink:href="http://docs.openstack.org/cli-reference/content/">
<citetitle>OpenStack Command-Line Reference</citetitle></link> for a
complete listing of <command>nova</command> commands and parameters.</para>
</note>
</step>
<step>
<para>Set the required parameters as environment variables to make running commands
easier. For example, you can add <parameter>--os-username</parameter> as a
<command>nova</command> option, or set it as an environment variable. To set
the user name, password, and tenant as environment variables, use:</para>
<screen><prompt>$</prompt> <userinput>export OS_USERNAME=joecool</userinput>
<prompt>$</prompt> <userinput>export OS_PASSWORD=coolword</userinput>
<prompt>$</prompt> <userinput>export OS_TENANT_NAME=coolu</userinput> </screen>
</step>
<step>
<para>Using the Identity Service, you are supplied with an authentication endpoint,
which Compute recognizes as the <literal>OS_AUTH_URL</literal>.</para>
<screen><prompt>$</prompt> <userinput>export OS_AUTH_URL=http://hostname:5000/v2.0</userinput>
<prompt>$</prompt> <userinput>export NOVA_VERSION=1.1</userinput></screen>
</step>
</procedure>
<section xml:id="section_euca2ools">
<title>Use the euca2ools commands</title>
<para>For a command-line interface to EC2 API calls, use the
<command>euca2ools</command> command-line tool. See <link
xlink:href="http://open.eucalyptus.com/wiki/Euca2oolsGuide_v1.3"
>http://open.eucalyptus.com/wiki/Euca2oolsGuide_v1.3</link></para>
</section>
<xi:include href="../../common/section_cli_nova_usage_statistics.xml"/>
</section>
<section xml:id="section_manage-logs">
<title>Manage logs</title>
<simplesect>
<title>Logging module</title>
<para>To specify a configuration file to change the logging behavior, add this line to
the <filename>/etc/nova/nova.conf</filename> file . To change the logging level,
such as (<literal>DEBUG</literal>, <literal>INFO</literal>,
<literal>WARNING</literal>, <literal>ERROR</literal>), use:
<programlisting language="ini">log-config=/etc/nova/logging.conf</programlisting></para>
<para>The logging configuration file is an ini-style configuration file, which must
contain a section called <literal>logger_nova</literal>, which controls the behavior
of the logging facility in the <literal>nova-*</literal> services. For
example:<programlisting language="ini">[logger_nova]
level = INFO
handlers = stderr
qualname = nova</programlisting></para>
<para>This example sets the debugging level to <literal>INFO</literal> (which is less
verbose than the default <literal>DEBUG</literal> setting). <itemizedlist>
<listitem>
<para>For more details on the logging configuration syntax, including the
meaning of the <literal>handlers</literal> and
<literal>quaname</literal> variables, see the <link
xlink:href="http://docs.python.org/release/2.7/library/logging.html#configuration-file-format"
>Python documentation on logging configuration file format
</link>f.</para>
</listitem>
<listitem>
<para>For an example <filename>logging.conf</filename> file with various
defined handlers, see the <link
xlink:href="http://docs.openstack.org/juno/config-reference/content/">
<citetitle>OpenStack Configuration
Reference</citetitle></link>.</para>
</listitem>
</itemizedlist>
</para>
</simplesect>
<simplesect>
<title>Syslog</title>
<para>You can configure OpenStack Compute services to send logging information to
<systemitem>syslog</systemitem>. This is useful if you want to use
<systemitem>rsyslog</systemitem>, which forwards the logs to a remote machine.
You need to separately configure the Compute service (nova), the Identity service
(keystone), the Image Service (glance), and, if you are using it, the Block Storage
service (cinder) to send log messages to <systemitem>syslog</systemitem>. To do so,
add the following lines to:</para>
<itemizedlist>
<listitem>
<para><filename>/etc/nova/nova.conf</filename></para>
</listitem>
<listitem>
<para><filename>/etc/keystone/keystone.conf</filename></para>
</listitem>
<listitem>
<para><filename>/etc/glance/glance-api.conf</filename></para>
</listitem>
<listitem>
<para><filename>/etc/glance/glance-registry.conf</filename></para>
</listitem>
<listitem>
<para><filename>/etc/cinder/cinder.conf</filename></para>
</listitem>
</itemizedlist>
<programlisting language="ini">verbose = False
debug = False
use_syslog = True
syslog_log_facility = LOG_LOCAL0</programlisting>
<para>In addition to enabling <systemitem>syslog</systemitem>, these settings also turn
off more verbose output and debugging output from the log.<note>
<para>Although the example above uses the same local facility for each service
(<literal>LOG_LOCAL0</literal>, which corresponds to
<systemitem>syslog</systemitem> facility <literal>LOCAL0</literal>), we
recommend that you configure a separate local facility for each service, as
this provides better isolation and more flexibility. For example, you may
want to capture logging information at different severity levels for
different services. <systemitem>syslog</systemitem> allows you to define up
to eight local facilities, <literal>LOCAL0, LOCAL1, ..., LOCAL7</literal>.
For more details, see the <systemitem>syslog</systemitem>
documentation.</para>
</note></para>
</simplesect>
<simplesect>
<title>Rsyslog</title>
<para><systemitem>rsyslog</systemitem> is a useful tool for setting up a centralized log
server across multiple machines. We briefly describe the configuration to set up an
<systemitem>rsyslog</systemitem> server; a full treatment of
<systemitem>rsyslog</systemitem> is beyond the scope of this document. We assume
<systemitem>rsyslog</systemitem> has already been installed on your hosts
(default for most Linux distributions).</para>
<para>This example provides a minimal configuration for
<filename>/etc/rsyslog.conf</filename> on the log server host, which receives
the log files:</para>
<programlisting language="bash"># provides TCP syslog reception
$ModLoad imtcp
$InputTCPServerRun 1024</programlisting>
<para>Add a filter rule to <filename>/etc/rsyslog.conf</filename> which looks for a host
name. The example below uses <replaceable>COMPUTE_01</replaceable> as an example of
a compute host name:</para>
<programlisting language="bash">:hostname, isequal, "<replaceable>COMPUTE_01</replaceable>" /mnt/rsyslog/logs/compute-01.log</programlisting>
<para>On each compute host, create a file named
<filename>/etc/rsyslog.d/60-nova.conf</filename>, with the following
content:</para>
<programlisting language="bash"># prevent debug from dnsmasq with the daemon.none parameter
*.*;auth,authpriv.none,daemon.none,local0.none -/var/log/syslog
# Specify a log level of ERROR
local0.error @@172.20.1.43:1024</programlisting>
<para>Once you have created this file, restart your <systemitem>rsyslog</systemitem>
daemon. Error-level log messages on the compute hosts should now be sent to your log
server.</para>
</simplesect>
<simplesect>
<title>Serial console</title>
<para>The serial console provides a useful way to examine kernel
output and other system messages during troubleshooting in cases
where an instance lacks network connectivity.</para>
<para>Releases prior to Juno only support read-only access via the
serial console using the <command>os-GetSerialOutput</command>
server action. Most cloud images enable this feature by
default. For more information, see
<link linkend="section_compute-empty-log-output">Troubleshoot
Compute</link>.</para>
<para>Juno and later releases support read-write access via the
serial console using the <command>os-GetSerialConsole</command>
server action. This feature also requires a websocket client to
access the serial console.</para>
<procedure>
<title>To configure read-write serial console access</title>
<para>On a compute node, edit the
<filename>/etc/nova/nova.conf</filename> file and complete
the following actions:</para>
<step>
<para>In the <parameter>[serial_console]</parameter> section,
enable the serial console:</para>
<programlisting language="ini">[serial_console]
...
enabled = true</programlisting>
</step>
<step>
<para>In the same section, configure the serial console proxy
similar to graphical console proxies:</para>
<programlisting language="ini">[serial_console]
...
base_url = ws://<replaceable>controller</replaceable>:6083/
listen = 0.0.0.0
proxyclient_address = <replaceable>MANAGEMENT_INTERFACE_IP_ADDRESS</replaceable></programlisting>
<para>The <option>base_url</option> option specifies the base
URL that clients receive from the API upon requesting a
serial console. Typically, this refers to the hostname of
the controller node.</para>
<para>The <option>listen</option> option specifies on
which network interface the
<systemitem class="service">nova-compute</systemitem>
listens for virtual console connections. Typically, this
uses 0.0.0.0 to enable listening on all interfaces.</para>
<para>The <option>proxyclient_address</option> specifies
to which network interface the proxy should connect.
Typically, this refers to the IP address of the
management interface.</para>
</step>
</procedure>
<para>Enabling read-write serial console access causes Compute
to add serial console information to the Libvirt XML file for
the instance. For example:</para>
<programlisting language="xml">&lt;console type='tcp'>
&lt;source mode='bind' host='127.0.0.1' service='10000'/>
&lt;protocol type='raw'/>
&lt;target type='serial' port='0'/>
&lt;alias name='serial0'/>
&lt;/console></programlisting>
<procedure>
<title>To access the serial console on an instance</title>
<step>
<para>Use the <command>nova get-serial-proxy</command>
command to retrieve the websocket URL for the
instance serial console:</para>
<screen><prompt>$</prompt> <userinput>nova get-serial-proxy <replaceable>INSTANCE_NAME</replaceable></userinput>
<computeroutput>+--------+-----------------------------------------------------------------+
| Type | Url |
+--------+-----------------------------------------------------------------+
| serial | ws://127.0.0.1:6083/?token=18510769-71ad-4e5a-8348-4218b5613b3d |
+--------+-----------------------------------------------------------------+</computeroutput></screen>
<para>Alternatively, use the API directly:</para>
<screen><prompt>$</prompt> <userinput>curl -i 'http://&lt;controller&gt;:8774/v2/&lt;tenant_uuid>/servers/&lt;instance_uuid>/action' \
-X POST \
-H "Accept: application/json" \
-H "Content-Type: application/json" \
-H "X-Auth-Project-Id: &lt;project_id>" \
-H "X-Auth-Token: &lt;auth_token>" \
-d '{"os-getSerialConsole": {"type": "serial"}}'</userinput></screen>
</step>
<step>
<para>Use Python websocket with the URL to generate
<literal>.send</literal>, <literal>.recv</literal>,
and <literal>.fileno</literal> methods for serial
console access. For example:</para>
<programlisting language="python">import websocket
ws = websocket.create_connection(
'ws://127.0.0.1:6083/?token=18510769-71ad-4e5a-8348-4218b5613b3d',
subprotocols=['binary', 'base64'])</programlisting>
<para>Alternatively, use a Python websocket client such as
<link xlink:href="https://github.com/larsks/novaconsole/"
/>.</para>
</step>
</procedure>
<note>
<para>Enabling the serial console disables typical instance logging
via the <command>nova console-log</command> command.
Kernel output and other system messages become invisible
unless actively viewing the serial console.</para>
</note>
</simplesect>
</section>
<xi:include href="section_compute-rootwrap.xml"/>
<xi:include href="section_compute-configure-migrations.xml"/>
<section xml:id="section_live-migration-usage">
<title>Migrate instances</title>
<para>Before starting migrations, review the <link
linkend="section_configuring-compute-migrations">Configure migrations
section</link>.</para>
<para>Migration provides a scheme to migrate running instances from one OpenStack Compute
server to another OpenStack Compute server.</para>
<procedure>
<title>To migrate instances</title>
<step>
<para>Look at the running instances, to get the ID of the instance you wish to
migrate.</para>
<screen><prompt>$</prompt> <userinput>nova list</userinput>
<computeroutput><![CDATA[+--------------------------------------+------+--------+-----------------+
| ID | Name | Status |Networks |
+--------------------------------------+------+--------+-----------------+
| d1df1b5a-70c4-4fed-98b7-423362f2c47c | vm1 | ACTIVE | private=a.b.c.d |
| d693db9e-a7cf-45ef-a7c9-b3ecb5f22645 | vm2 | ACTIVE | private=e.f.g.h |
+--------------------------------------+------+--------+-----------------+]]></computeroutput></screen>
</step>
<step>
<para>Look at information associated with that instance. This example uses 'vm1'
from above.</para>
<screen><prompt>$</prompt> <userinput>nova show d1df1b5a-70c4-4fed-98b7-423362f2c47c</userinput>
<computeroutput><![CDATA[+-------------------------------------+----------------------------------------------------------+
| Property | Value |
+-------------------------------------+----------------------------------------------------------+
...
| OS-EXT-SRV-ATTR:host | HostB |
...
| flavor | m1.tiny |
| id | d1df1b5a-70c4-4fed-98b7-423362f2c47c |
| name | vm1 |
| private network | a.b.c.d |
| status | ACTIVE |
...
+-------------------------------------+----------------------------------------------------------+]]></computeroutput></screen>
<para>In this example, vm1 is running on HostB.</para>
</step>
<step>
<para>Select the compute node to which instances will be migrated to:</para>
<screen><prompt>#</prompt> <userinput>nova service-list</userinput>
<computeroutput>+------------------+------------+----------+---------+-------+----------------------------+-----------------+
| Binary | Host | Zone | Status | State | Updated_at | Disabled Reason |
+------------------+------------+----------+---------+-------+----------------------------+-----------------+
| nova-consoleauth | HostA | internal | enabled | up | 2014-03-25T10:33:25.000000 | - |
| nova-scheduler | HostA | internal | enabled | up | 2014-03-25T10:33:25.000000 | - |
| nova-conductor | HostA | internal | enabled | up | 2014-03-25T10:33:27.000000 | - |
| nova-compute | HostB | nova | enabled | up | 2014-03-25T10:33:31.000000 | - |
| nova-compute | HostC | nova | enabled | up | 2014-03-25T10:33:31.000000 | - |
| nova-cert | HostA | internal | enabled | up | 2014-03-25T10:33:31.000000 | - |
+------------------+------------+----------+---------+-------+----------------------------+-----------------+</computeroutput></screen>
<para>In this example, HostC can be picked up because <systemitem class="service"
>nova-compute</systemitem> is running on it.</para>
</step>
<step>
<para>Ensure that HostC has enough resources for migration.</para>
<screen><prompt>#</prompt> <userinput>nova host-describe HostC</userinput>
<computeroutput>+-----------+------------+-----+-----------+---------+
| HOST | PROJECT | cpu | memory_mb | disk_gb |
+-----------+------------+-----+-----------+---------+
| HostC | (total) | 16 | 32232 | 878 |
| HostC | (used_now) | 13 | 21284 | 442 |
| HostC | (used_max) | 13 | 21284 | 442 |
| HostC | p1 | 13 | 21284 | 442 |
| HostC | p2 | 13 | 21284 | 442 |
+-----------+------------+-----+-----------+---------+</computeroutput></screen>
<itemizedlist>
<listitem>
<para><emphasis role="bold">cpu:</emphasis>the number of cpu</para>
</listitem>
<listitem>
<para><emphasis role="bold">memory_mb:</emphasis>total amount of memory (in
MB)</para>
</listitem>
<listitem>
<para><emphasis role="bold">disk_gb:</emphasis>total amount of space for
NOVA-INST-DIR/instances (in GB)</para>
</listitem>
<listitem>
<para><emphasis role="bold">1st line shows </emphasis>total amount of
resources for the physical server.</para>
</listitem>
<listitem>
<para><emphasis role="bold">2nd line shows </emphasis>currently used
resources.</para>
</listitem>
<listitem>
<para><emphasis role="bold">3rd line shows </emphasis>maximum used
resources.</para>
</listitem>
<listitem>
<para><emphasis role="bold">4th line and under</emphasis> shows the resource
for each project.</para>
</listitem>
</itemizedlist>
</step>
<step>
<para>Use the <command>nova live-migration</command> command to migrate the
instances:<screen><prompt>$</prompt> <userinput>nova live-migration <replaceable>SERVER</replaceable> <replaceable>HOST_NAME</replaceable></userinput></screen></para>
<para>Where <replaceable>SERVER</replaceable> can be the ID or name of the instance.
For example:</para>
<screen><prompt>$</prompt> <userinput>nova live-migration d1df1b5a-70c4-4fed-98b7-423362f2c47c HostC</userinput><computeroutput>
<![CDATA[Migration of d1df1b5a-70c4-4fed-98b7-423362f2c47c initiated.]]></computeroutput></screen>
<para>Ensure instances are migrated successfully with <command>nova list</command>.
If instances are still running on HostB, check log files (src/dest <systemitem
class="service">nova-compute</systemitem> and <systemitem class="service"
>nova-scheduler</systemitem>) to determine why.</para>
<note>
<para>Although the <command>nova</command> command is called
<command>live-migration</command>, under the default Compute
configuration options, the instances are suspended before migration.</para>
<para>For more details, see <link
xlink:href="http://docs.openstack.org/juno/config-reference/content/list-of-compute-config-options.html"
>Configure migrations</link> in <citetitle>OpenStack Configuration
Reference</citetitle>.</para>
</note>
</step>
</procedure>
</section>
<xi:include href="../../common/section_compute-configure-console.xml"/>
<xi:include href="section_compute-configure-service-groups.xml"/>
<xi:include href="section_compute-security.xml"/>
<xi:include href="section_compute-recover-nodes.xml"/>
</section>