(Linux only)

In FSS environments, hot-relocation employs a policy-based mechanism for healing storage failures. Storage failures may include disk media failure or node failures that render storage inaccessible. This mechanism uses tunables to determine the amount of time that VxVM waits for the storage to come online before initiating hot-relocation. If the storage fails to come online within the specified time interval, VxVM relocates the failed disk.

VxVM uses the following tunables:

The default value for the tunables is 30 minutes. You can modify the tunable value to suit your business needs. In the current implementation, VxVM does not differentiate between disk media and node failures. As a result, both tunables will have the same value. For example, if you set the value of thestorage_reloc_timeout tunable to 15, then VxVM will set the value of thenode_reloc_timeout tunable also to 15. Similarly, if you set thenode_reloc_timeout tunable to a specific value, VxVM sets the same value for the storage_reloc_timeout tunable. You can use the vxtune command to view or update the tunable settings.

The hot-relocation process varies slightly for DAS environments as compared to shared environments. When a DAS disk fails, VxVM attempts to relocate the data volume along with its associated DCO volume (even though the DCO may not have failed) to another disk on the same node for performance reasons. During relocation, VxVM gives first preference to available spare disks, failing which VxVM looks for eligible free space.

Hot-relocation in FSS environments is supported only on new disk groups created with disk group version 230. Existing disk groups cannot be used for relocation.

For more information see the InfoScale storage administration guides.