Chapter 10. Rebooting Nodes
Some situations require a reboot of nodes in the undercloud and overcloud. The following procedures show how to reboot different node types. Be aware of the following notes:
- If rebooting all nodes in one role, it is advisable to reboot each node individually. This helps retain services for that role during the reboot.
- If rebooting all nodes in your OpenStack Platform environment, use the following list to guide the reboot order:
Recommended Node Reboot Order
- Reboot the director
- Reboot Controller nodes
- Reboot standalone Ceph MON nodes
- Reboot Ceph Storage nodes
- Reboot Compute nodes
- Reboot object Storage nodes
10.1. Rebooting the Director
To reboot the director node, follow this process:
Reboot the node:
$ sudo reboot
- Wait until the node boots.
When the node boots, check the status of all services:
$ sudo systemctl list-units "openstack*" "neutron*" "openvswitch*"
NoteIt might take approximately 10 minutes for the
openstack-nova-computeto become active after a reboot.Verify the existence of your Overcloud and its nodes:
$ source ~/stackrc $ openstack server list $ openstack baremetal node list $ openstack stack list
10.2. Rebooting Controller Nodes
To reboot the Controller nodes, follow this process:
Select a node to reboot. Log into it and stop the cluster before rebooting:
$ sudo pcs cluster stop
Reboot the cluster:
$ sudo reboot
The remaining Controller Nodes in the cluster retain the high availability services during the reboot.
- Wait until the node boots.
Re-enable the cluster for the node:
$ sudo pcs cluster start
Log into the node and check the cluster status:
$ sudo pcs status
The node rejoins the cluster.
NoteIf any services fail after the reboot, run sudo
pcs resource cleanup, which cleans the errors and sets the state of each resource toStarted. If any errors persist, contact Red Hat and request guidance and assistance.Check all
systemdservices on the Controller Node are active:$ sudo systemctl list-units "openstack*" "neutron*" "openvswitch*"
- Log out of the node, select the next Controller Node to reboot, and repeat this procedure until you have rebooted all Controller Nodes.
10.3. Rebooting standalone Ceph MON nodes
To reboot the Ceph MON nodes, follow this process:
- Log into a Ceph MON node.
Reboot the node:
$ sudo reboot
- Wait until the node boots and rejoins the MON cluster.
Repeat these steps for each MON node in the cluster.
10.4. Rebooting Ceph Storage Nodes
To reboot the Ceph Storage nodes, follow this process:
Log into a Ceph MON or Controller node and disable Ceph Storage cluster rebalancing temporarily:
$ sudo ceph osd set noout $ sudo ceph osd set norebalance
- Select the first Ceph Storage node to reboot and log into it.
Reboot the node:
$ sudo reboot
- Wait until the node boots.
Log into the node and check the cluster status:
$ sudo ceph -s
Check that the
pgmapreports allpgsas normal (active+clean).- 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 into a Ceph MON or Controller node and enable cluster rebalancing again:
$ sudo ceph osd unset noout $ sudo ceph osd unset norebalance
Perform a final status check to verify the cluster reports
HEALTH_OK:$ sudo ceph status
10.5. Rebooting Compute Nodes
Reboot each Compute node individually and ensure zero downtime of instances in your OpenStack Platform environment. This involves the following workflow:
- Select a Compute node to reboot
- Migrate its instances to another Compute node
- Reboot the empty Compute node
List all Compute nodes and their UUIDs:
$ nova list | grep "compute"
Select a Compute node to reboot and first migrate its instances using the following process:
From the undercloud, select a Compute Node to reboot and disable it:
$ source ~/overcloudrc $ openstack compute service list $ openstack compute service set [hostname] nova-compute --disable
List all instances on the Compute node:
$ openstack server list --host [hostname] --all-projects
Migrate each instance from the disabled host. Use one of the following commands:
Migrate the instance to a specific host of your choice:
$ openstack server migrate [instance-id] --live [target-host]--wait
Let
nova-schedulerautomatically select the target host:$ nova live-migration [instance-id]
NoteThe
novacommand might cause some deprecation warnings, which are safe to ignore.
- Wait until migration completes.
Confirm the instance has migrated from the Compute node:
$ openstack server list --host [hostname] --all-projects
- Repeat this step until you have migrated all instances from the Compute Node.
For full instructions on configuring and migrating instances, see Chapter 8, Migrating Virtual Machines Between Compute Nodes.
Reboot the Compute node using the following process
Log into the Compute Node and reboot it:
$ sudo reboot
- Wait until the node boots.
Enable the Compute Node again:
$ source ~/overcloudrc $ openstack compute service set [hostname] nova-compute --enable
- Select the next node to reboot.
10.6. Rebooting Object Storage Nodes
To reboot the Object Storage nodes, follow this process:
Select a Object Storage node to reboot. Log into it and reboot it:
$ sudo reboot
- Wait until the node boots.
Log into the node and check the status:
$ sudo systemctl list-units "openstack-swift*"
- Log out of the node and repeat this process on the next Object Storage node.
