Managing clusters
How to expand and shrink a cluster in a homogeneous Content Software for File system configuration.
Shrinking a cluster using the CLI
The procedures are described that are involved in the shrinking of a cluster and may be required when it is necessary to reallocate cluster hardware.
Options for shrinking a cluster
Cluster shrinking can involve either the removal of some of the assigned SSDs or the removal of hosts from the system. The following operations are available:
- Listing all the drives and their states, in order to receive a view of currently-allocated resources and their status.
- Deactivating drives as the first step before removing a host.
- Removing (a subset of) SSD drives allocated for the cluster.
- Deactivating hosts, which can be used after deactivating drives in preparation for the removal of the host.
- Removing hosts in order to complete the cluster shrinking.
Listing drives and their states using the CLI
Use this command to display a list of all the drives in the cluster and their status.
Deactivating a drive using the CLI
Running this command will redistribute the stored data on the remaining drives and can be performed on multiple drives.
Drive deactivation starts an asynchronous process known as phasing out, which is a gradual redistribution of the data between the remaining drives in the system. On completion, the phased-out drive is in an inactive state, that is, not in use by the Content Software for File system, but still appearing in the list of drives.
To deactivate a drive, run the following command:
weka cluster drive deactivate <uuids>
| Name | Type | Value | Limitations | Mandatory | Default |
| uuids | Comma-separated strings | Comma-separated drive identifiers | Yes |
Removing a drive using the CLI
This command is used to completely remove a drive from the cluster. After removal, the drive will not be recoverable. To remove a drive, run the following command:
weka cluster drive remove <uuids>
| Name | Type | Value | Limitations | Mandatory | Default |
| uuids | Comma-separated strings | Comma-separated strings | Yes |
Deactivating an entire host using the CLI
his command is used as the first step when seeking to shrink a cluster. Running this command will automatically deactivate all the host's drives. To deactivate an entire host, run the following command:
weka cluster host deactivate <host-ids> [--allow-unavailable-host]
| Name | Type | Value | Limitations | Mandatory | Default |
| host-ids | Space-separated integers | Space-separated host identifiers | Yes | ||
| allow-unavailable-host | Boolean | Allow deactivation of an unavailable host | If the host returns, it will join the cluster in an active state | No | No |
Removing a host using the CLI
Running this command will eliminate the host from the cluster, that is, the host will switch to the stem mode after the removal, at which point it can be reallocated either to another cluster or purpose. To remove the host from the cluster, run the following command:
weka cluster host remove <host-id>
| Name | Type | Value | Limitations | Mandatory | Default |
| host-id | Comma-separated strings | Comma-separated host identifiers | Yes |