Note
To support hot plugging, Swarm requires control of all of the volumes (disk.volumes = all).
I/O errors are recorded in the log if the Health Processor is actively scanning a drive when it is removed. These errors are expected and do not indicate a problem.
When a drive is removed, volume recovery (FVR) and erasure coding recovery (ECR) are both triggered, which includes creating new replicas or erasure set segments for objects stored on that drive.
Both recovery processes stop if a drive is inserted in the same node or in a different node in the cluster. There is a temporary state of over-replication because the returned volume has replicas or segments already recreated elsewhere. In time, the excess replicas or segments are deleted.
Swarm recognizes, formats, and mounts a drive as a new volume if a non-Swarm drive is inserted in a node.
A Swarm-formatted drive continues to function as a volume without loss of data if inserted, either into the same node or into a different node.
A volume remains retired if a previously retired Swarm-formatted drive is inserted. No manual configuration or intervention is required.
Messages display in logs and in the Swarm Admin Console to indicate a drive was inserted or removed.
Wait 2 minutes between drive insertions to ensure new drives are evenly distributed across multiple nodes running on the chassis if inserting multiple drives into the same server chassis.
Caution
When adding or relocating volumes to a node, ensure the node has enough RAM to handle them, else the node may be unable to mount some of the volumes.
Warning
Do not move Swarm drives between disk array controller types after they have been formatted by Swarm. Each controller reports available drive space to Swarm matched with the controller. For example, many controllers claim the last section of the drive, reducing the total available space. The new controller may claim additional drive space not reported to Swarm, so Swarm may attempt to write data to non-existing space, generating I/O errors if drives are switch with another controller.