3.10. Releasing nodes from the storage cluster¶

To release a node means to remove it from the cluster. As the node may be running services needed by the cluster, do the following prior to releasing it, to avoid cluster degradation:

1. If the node runs one of the three required metadata services, add a metadata role to another node. You need to make sure that the cluster has at least three metadata services running at any time.
2. If the node has any access points, make sure that the same access points are configured on other nodes in the cluster as well.
3. If the node is in an iSCSI target group, remove it from the target group first.
4. If the node has an S3 or backup gateway, reconfigure the DNS for S3 and Backup Gateway access points to remove the node from the DNS records. Next, release the node from the S3 and Backup Gateway clusters in the corresponding sections of the Storage services screen.
5. If the node is in the compute cluster, remove it from the compute cluster, first.
6. Make sure the cluster has enough storage space to accommodate the data from the released node.

Once you initiate the release, the cluster will start replicating data chunks that were stored on the released node, and then distributing them among other storage nodes in the cluster. Depending on the amount of data to replicate, the process may take as much as several hours.

If necessary, you can also release a node forcibly; that is, without replication.

To release a node from a cluster, do the following:

1. On the Infrastructure > Nodes screen, click the line with the node to release.
2. On the right pane, click Release node.
3. (Optional, highly not recommended) To release the node without data migration, select Release without data migration.
4. Click Release. The released node will be displayed as Unassigned on the Infrastructure > Nodes screen.