Chapter 7. Rebooting the overcloud after the upgrade
After upgrading your Red Hat OpenStack environment, reboot your overcloud. The reboot updates the nodes with any associated kernel, system-level, and container component updates. These updates may provide performance and security benefits.
Plan downtime to perform the following reboot procedures.
7.1. Rebooting controller and composable nodes Copy linkLink copied to clipboard!
The following procedure reboots controller nodes and standalone nodes based on composable roles. This excludes Compute nodes and Ceph Storage nodes.
Procedure
- Log in to the node that you want to reboot.
Optional: If the node uses Pacemaker resources, stop the cluster:
sudo pcs cluster stop
[heat-admin@overcloud-controller-0 ~]$ sudo pcs cluster stop
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Reboot the node:
sudo reboot
[heat-admin@overcloud-controller-0 ~]$ sudo reboot
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Wait until the node boots.
Check the services. For example:
If the node uses Pacemaker services, check that the node has rejoined the cluster:
sudo pcs status
[heat-admin@overcloud-controller-0 ~]$ sudo pcs status
Copy to Clipboard Copied! Toggle word wrap Toggle overflow If the node uses Systemd services, check that all services are enabled:
sudo systemctl status
[heat-admin@overcloud-controller-0 ~]$ sudo systemctl status
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Repeat these steps for all Controller and composable nodes.
7.2. Rebooting a Ceph Storage (OSD) cluster Copy linkLink copied to clipboard!
The following procedure reboots a cluster of Ceph Storage (OSD) nodes.
Procedure
Log in to a Ceph MON or Controller node and disable Ceph Storage cluster rebalancing temporarily:
sudo ceph osd set noout sudo ceph osd set norebalance
$ sudo ceph osd set noout $ sudo ceph osd set norebalance
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Select the first Ceph Storage node to reboot and log into it.
Reboot the node:
sudo reboot
$ sudo reboot
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Wait until the node boots.
Log in to a Ceph MON or Controller node and check the cluster status:
sudo ceph -s
$ sudo ceph -s
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Check that the
pgmap
reports allpgs
as normal (active+clean
).- Log out of the Ceph MON or Controller node, reboot the next Ceph Storage node, and check its status. Repeat this process until you have rebooted all Ceph storage nodes.
When complete, log into a Ceph MON or Controller node and enable cluster rebalancing again:
sudo ceph osd unset noout sudo ceph osd unset norebalance
$ sudo ceph osd unset noout $ sudo ceph osd unset norebalance
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Perform a final status check to verify the cluster reports
HEALTH_OK
:sudo ceph status
$ sudo ceph status
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
7.3. Rebooting Compute nodes Copy linkLink copied to clipboard!
Rebooting a Compute node involves the following workflow:
- Select a Compute node to reboot and disable it so that it does not provision new instances.
- Migrate the instances to another Compute node to minimise instance downtime.
- Reboot the empty Compute node and enable it.
Procedure
-
Log in to the undercloud as the
stack
user. To identify the Compute node that you intend to reboot, list all Compute nodes:
source ~/stackrc
$ source ~/stackrc (undercloud) $ openstack server list --name compute
Copy to Clipboard Copied! Toggle word wrap Toggle overflow From the overcloud, select a Compute Node and disable it:
source ~/overcloudrc
$ source ~/overcloudrc (overcloud) $ openstack compute service list (overcloud) $ openstack compute service set <hostname> nova-compute --disable
Copy to Clipboard Copied! Toggle word wrap Toggle overflow List all instances on the Compute node:
(overcloud) $ openstack server list --host <hostname> --all-projects
(overcloud) $ openstack server list --host <hostname> --all-projects
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Migrate your instances. For more information on migration strategies, see Migrating virtual machines between Compute nodes.
Log into the Compute Node and reboot it:
sudo reboot
[heat-admin@overcloud-compute-0 ~]$ sudo reboot
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Wait until the node boots.
Enable the Compute node:
source ~/overcloudrc
$ source ~/overcloudrc (overcloud) $ openstack compute service set <hostname> nova-compute --enable
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Verify that the Compute node is enabled:
(overcloud) $ openstack compute service list
(overcloud) $ openstack compute service list
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
7.4. Rebooting Compute HCI nodes Copy linkLink copied to clipboard!
The following procedure reboots Compute hyperconverged infrastructure (HCI) nodes.
Procedure
Log in to a Ceph MON or Controller node and disable Ceph Storage cluster rebalancing temporarily:
sudo ceph osd set noout sudo ceph osd set norebalance
$ sudo ceph osd set noout $ sudo ceph osd set norebalance
Copy to Clipboard Copied! Toggle word wrap Toggle overflow -
Log in to the undercloud as the
stack
user. List all Compute nodes and their UUIDs:
source ~/stackrc
$ source ~/stackrc (undercloud) $ openstack server list --name compute
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Identify the UUID of the Compute node you aim to reboot.
From the undercloud, select a Compute node and disable it:
source ~/overcloudrc
$ source ~/overcloudrc (overcloud) $ openstack compute service list (overcloud) $ openstack compute service set [hostname] nova-compute --disable
Copy to Clipboard Copied! Toggle word wrap Toggle overflow List all instances on the Compute node:
(overcloud) $ openstack server list --host [hostname] --all-projects
(overcloud) $ openstack server list --host [hostname] --all-projects
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Use one of the following commands to migrate your instances:
Migrate the instance to a specific host of your choice:
(overcloud) $ openstack server migrate [instance-id] --live [target-host]--wait
(overcloud) $ openstack server migrate [instance-id] --live [target-host]--wait
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Let
nova-scheduler
automatically select the target host:(overcloud) $ nova live-migration [instance-id]
(overcloud) $ nova live-migration [instance-id]
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Live migrate all instances at once:
nova host-evacuate-live [hostname]
$ nova host-evacuate-live [hostname]
Copy to Clipboard Copied! Toggle word wrap Toggle overflow NoteThe
nova
command might cause some deprecation warnings, which are safe to ignore.
- Wait until the migration completes.
Confirm that the migration was successful:
(overcloud) $ openstack server list --host [hostname] --all-projects
(overcloud) $ openstack server list --host [hostname] --all-projects
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Continue migrating instances until none remain on the chosen Compute node.
Log in to a Ceph MON or a Controller node and check the cluster status:
sudo ceph -s
$ sudo ceph -s
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Check that the
pgmap
reports allpgs
as normal (active+clean
).Reboot the Compute HCI node:
sudo reboot
$ sudo reboot
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Wait until the node boots.
Enable the Compute node again:
source ~/overcloudrc
$ source ~/overcloudrc (overcloud) $ openstack compute service set [hostname] nova-compute --enable
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Verify that the Compute node is enabled:
(overcloud) $ openstack compute service list
(overcloud) $ openstack compute service list
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - Log out of the node, reboot the next node, and check its status. Repeat this process until you have rebooted all Ceph storage nodes.
When complete, log in to a Ceph MON or Controller node and enable cluster rebalancing again:
sudo ceph osd unset noout sudo ceph osd unset norebalance
$ sudo ceph osd unset noout $ sudo ceph osd unset norebalance
Copy to Clipboard Copied! Toggle word wrap Toggle overflow Perform a final status check to verify the cluster reports
HEALTH_OK
:sudo ceph status
$ sudo ceph status
Copy to Clipboard Copied! Toggle word wrap Toggle overflow