Customize Virtual Device Engine › Virtual Device Channel Paths › CHPID Failover

CHPID Failover

If one of the CHPIDs that the Virtual Devices are using is taken offline, CA Vtape interacts with the channel path recovery feature of the operating system to switch dynamically to the next available CHPID in the assigned list. As with all devices, when the last assigned CHPID goes offline, the affected Virtual Devices are boxed or fenced. If the Virtual Devices are in use, take the following steps:

1. Cancel the affected jobs.
2. Bring back online at least one of the assigned CHPIDs.
3. Stop and start CA Vtape.
4. Resubmit the affected jobs.

The CHPID list is one directional. When the first CHPID in the list is taken offline, the Virtual Devices are failed over to the next CHPID in the list. When the second CHPID in the list is taken offline, the Virtual Devices are failed over to the third CHPID in the list. Bringing the first CHPID in the list back online does not matter. Failover cannot go back to a CHPID previously used. Failover also cannot wrap back to the first CHPID in the list when the last CHPID in the list is taken offline. After the CHPID failover occurs, the failed CHPID can only be reused if CA Vtape is stopped and started.