Managing the cell¶
Add a compute to a cell¶
To increase resource capacity of a running cell, you can start more servers of a selected role. For more details on how to add nodes see Scaling overcloud roles.
After the node got deployed, login to one of the overcloud controllers and run the cell host discovery:
CTRL=overcloud-controller-0
CTRL_IP=$(openstack server list -f value -c Networks --name $CTRL | sed 's/ctlplane=//')
# CONTAINERCLI can be either docker or podman
export CONTAINERCLI='docker'
# run cell host dicovery
ssh heat-admin@${CTRL_IP} sudo ${CONTAINERCLI} exec -i -u root nova_api \
nova-manage cell_v2 discover_hosts --by-service --verbose
# verify the cell hosts
ssh heat-admin@${CTRL_IP} sudo ${CONTAINERCLI} exec -i -u root nova_api \
nova-manage cell_v2 list_hosts
# add new node to the availability zone
source overcloudrc
(overcloud) $ openstack aggregate add host <cell name> <compute host>
Note
Optionally the cell uuid cal be specificed to the discover_hosts and list_hosts command to only target against a specific cell.
Delete a compute from a cell¶
As initial step migrate all instances off the compute.
From one of the overcloud controllers, delete the computes from the cell:
source stackrc CTRL=overcloud-controller-0 CTRL_IP=$(openstack server list -f value -c Networks --name $CTRL | sed 's/ctlplane=//') # CONTAINERCLI can be either docker or podman export CONTAINERCLI='docker' # list the cell hosts ssh heat-admin@${CTRL_IP} sudo ${CONTAINERCLI} exec -i -u root nova_api \ nova-manage cell_v2 list_hosts # delete a node from a cell ssh heat-admin@${CTRL_IP} sudo ${CONTAINERCLI} exec -i -u root nova_api \ nova-manage cell_v2 delete_host --cell_uuid <uuid> --host <compute>
Delete the node from the cell stack
Delete the resource providers from placement
This step is required as otherwise adding a compute node with the same hostname will make it to fail to register and update the resources with the placement service.:
sudo yum install python2-osc-placement openstack resource provider list +--------------------------------------+---------------------------------------+------------+ | uuid | name | generation | +--------------------------------------+---------------------------------------+------------+ | 9cd04a8b-5e6c-428e-a643-397c9bebcc16 | computecell1-novacompute-0.site1.test | 11 | +--------------------------------------+---------------------------------------+------------+ openstack resource provider delete 9cd04a8b-5e6c-428e-a643-397c9bebcc16
Delete a cell¶
As initial step delete all instances from the cell.
From one of the overcloud controllers, delete all computes from the cell:
CTRL=overcloud-controller-0 CTRL_IP=$(openstack server list -f value -c Networks --name $CTRL | sed 's/ctlplane=//') # CONTAINERCLI can be either docker or podman export CONTAINERCLI='docker' # list the cell hosts ssh heat-admin@${CTRL_IP} sudo ${CONTAINERCLI} exec -i -u root nova_api \ nova-manage cell_v2 list_hosts # delete a node from a cell ssh heat-admin@${CTRL_IP} sudo ${CONTAINERCLI} exec -i -u root nova_api \ nova-manage cell_v2 delete_host --cell_uuid <uuid> --host <compute>
On the cell controller delete all deleted instances from the database:
CELL_CTRL=cell1-cellcontrol-0 CELL_CTRL_IP=$(openstack server list -f value -c Networks --name $CELL_CTRL | sed 's/ctlplane=//') # CONTAINERCLI can be either docker or podman export CONTAINERCLI='docker' ssh heat-admin@${CELL_CTRL_IP} sudo ${CONTAINERCLI} exec -i -u root nova_conductor \ nova-manage db archive_deleted_rows --until-complete --verbose
From one of the overcloud controllers, delete the cell:
CTRL=overcloud-controller-0 CTRL_IP=$(openstack server list -f value -c Networks --name $CTRL | sed 's/ctlplane=//') # CONTAINERCLI can be either docker or podman export CONTAINERCLI='docker' # list the cells ssh heat-admin@${CTRL_IP} sudo ${CONTAINERCLI} exec -i -u root nova_api \ nova-manage cell_v2 list_cells # delete the cell ssh heat-admin@${CTRL_IP} sudo ${CONTAINERCLI} exec -i -u root nova_api \ nova-manage cell_v2 delete_cell --cell_uuid <uuid>
Delete the cell stack:
openstack stack delete <stack name> --wait --yes && openstack overcloud plan delete <stack name>Note
If the cell consist of a controller and compute stack, delete as a first step the compute stack and then the controller stack.
From a system which can reach the placement endpoint, delete the resource providers from placement
This step is required as otherwise adding a compute node with the same hostname will make it to fail to register as a resource with the placement service. In case of Centos/RHEL 8 the required packages is python3-osc-placement:
sudo yum install python2-osc-placement source overcloudrc openstack resource provider list +--------------------------------------+---------------------------------------+------------+ | uuid | name | generation | +--------------------------------------+---------------------------------------+------------+ | 9cd04a8b-5e6c-428e-a643-397c9bebcc16 | computecell1-novacompute-0.site1.test | 11 | +--------------------------------------+---------------------------------------+------------+ openstack resource provider delete 9cd04a8b-5e6c-428e-a643-397c9bebcc16
Updating a cell¶
Each stack in a multi-stack cell deployment must be updated to perform a full minor update across the entire deployment.
Cells can be updated just like the overcloud nodes following update procedure described in Updating Content on Overcloud Nodes and using appropriate stack name for update commands.
The control plane and cell controller stack should be updated first by completing all the steps from the minor update procedure.
Once the control plane stack is updated, re-run the export command to recreate the required input files for each separate cell stack.
Note
Before re-running the export command, backup the previously used input file so that the previous versions are not overwritten. In the event that a separate cell stack needs a stack update operation performed prior to the minor update procedure, the previous versions of the exported files should be used.
