Ownership takeover
If a TS7700 Cluster fails, ownership transfer of the volumes that it owned is not automatic. In order for another cluster to access and manage those volumes, the failed TS7700 Cluster is placed in an ownership takeover mode.
The ownership takeover modes are set through the TS7700's System
Management Interface Tool panel. Three modes are provided:
- Read Ownership Takeover
- When Read Ownership Takeover (ROT) is enabled for a failed cluster, volume ownership is allowed to be taken from a failed TS7700 Cluster by any other available TS7700 Cluster. Only read access to the volume is allowed through the remaining TS7700 Clusters if the volume is taken over. When ownership for a volume has been taken in this mode, any operation attempting to modify data on that volume or change its attributes fails.
- Write Ownership Takeover
- When Write Ownership Takeover (WOT) is enabled for a failed TS7700 Cluster, volume ownership is allowed to be taken from a failed TS7700 Cluster. Full access is allowed through the remaining available TS7700 Clusters in the Grid.
- Service Preparation/Service Mode
- When a TS7700 Cluster is placed into service preparation and successfully enters the service mode, ownership of its volumes is allowed to be taken by the remaining available TS7700 Clusters in the Grid. Full access is allowed.