The storage cluster is designed to automatically adapt when a volume (hard drive) or node fails for any reason. Swarm checks every storage cluster volume during the node startup procedure, and it tracks any gaps in service that trigger a status change:

• A volume is considered "stale" and the contents cannot be used unless an administrator overrides this process if disconnected from the cluster for more than 2 weeks.

• A node and all volumes are considered stale and cannot be used if it is shut down for more than 2 weeks.

The "stale" status is triggered by a service gap of 2 weeks, which is the default value for the disk.obsoleteTimeout setting.

Force a volume remount by modifying the disk.volumes setting and adding the :k (keep) policy option. Return them to service dynamically (either remounting or reformatting) using SNMP. (v9.3)

Reformatting Volumes (Recommended)

Reformatting the volume allows it to be filled by the health processor (HP) in an orderly fashion. Performing this prevents creating excessive work for the health processor and prevents generating trapped space needed to be reclaimed.

With support tools updated, you can use swarmctl from your support tools directory to return a disk to service by reformatting the disk. This command does not work when run from CentOS 6 (like the CSN) but will work from any SCS, Content Gateway, or Elasticsearch node. You can specify the disk or, if left blank, it will reformat all stale disks on that node.

On any CentOS 6 based system, use SNMP for this procedure using the MIBs in our support tools directory using the read/write SNMP string as shown here. In this case, the MIBs are present in the current directory.

Remounting Volumes

It is rarely desirable to remount a volume that has stale content. The volume's missing content is recovered by this time and the cluster has its full complement of replicas of the cluster's content. Adding extra replicas creates work for the health processor to sift through the replicas, cleaning up redundant and obsolete copies. This cleanup creates trapped space in the cluster that take several HP cycles to reclaim.

With support tools updated, you can use swarmctl from your support tools directory to return a disk to service by re-mounting the disk. This command does not work when run from CentOS 6 (like the CSN) but will work from any SCS, Content Gateway, or Elasticsearch node. You can specify the disk or, if left blank, it will remount all stale disks on that node.

You will see these ANNOUNCE level messages in the castor.log file:

On a CSN or other CentOS server, you must use SNMP for this procedure using the MIBs using the read/write SNMP string as shown here. In this case, the MIBs are present in the current directory.