HP XP P9500 Storage - Manual (Page 55)

7. If using RAID Manager, continue with this step. If using Remote Web Console, skip to the next
step.
1.
When the Continuous Access Synchronous pair creation operation is completed, execute
the RAID Manager horctakeover command on the primary system S-VOL. This reverses
the P-VOL/S-VOL relationship; the S-VOL on the primary system now becomes the P-VOL.
2. On the primary and secondary systems, add the quorum disk.
3. Perform the Pairsplit-r operation on the primary system P-VOL to split the Continuous
Access Synchronous pair.
4. Perform the Pairresync operation on the P-VOL using Remote Web Console to change
the Continuous Access Synchronous pair to an ESAM pair.
8. If using Remote Web Console, continue as follows:
1.
Make sure the Continuous Access Synchronous pair creation operation completed, then
release the Continuous Access Synchronous pair.
2. On the primary and secondary systems, add the quorum disk.
3. On the primary system, create an ESAM pair.
9. On both primary and secondary systems, make sure that the pair volume's Type field is ESAM.
10. Using multipath software, vary the owner and non-owner paths online.
11. Restart host I/O.
Restoring owner and non-owner paths
If failures occur in both the owner and non-owner paths, the paths must be restored in the correct
order. To prevent unexpected failover or failback, first restore the path to the storage system that
will allow host operations to resume, then restore the other path.
The following table shows the behavior that will occur given the order for restoring paths.
Table 8 Order for restoring paths
Will failover or failback occur? Order for restoring paths Volume receiving host I/O
No. 1. Owner path Primary system P-VOL
2. Non-owner path
Yes, if data in the S-VOL is newer than in the
P-VOL, failover occurs after the non-owner path is 1. Non-Owner path
2. Owner path
restored. However, failover does not occur if data
in the S-VOL is older. Check this by viewing the
VOL Access column on the Pair Operations
window for the P-VOL. If Access (Lock) displays,
then the P-VOL is receiving host I/O.
Yes, failover occurs after the owner path is
restored. However, if data in the primary system 1. Owner path
2. Non-owner path
Secondary system P-VOL
(original S-VOL)
S-VOL is older, failover does not occur. Check this
by viewing the VOL Access column on the Pair
Operations window for the secondary system
P-VOL. If Access (Lock) displays, then this volume
is receiving host I/O.
No. 1. Non-Owner path
2. Owner path
Allowing host I/O to an out-of-date S-VOL
If recovery operations are undertaken on a primary system, the S-VOL might be needed to continue
host operations, even though its data is older than the P-VOL's data.
In this case, call HP Technical Support and ask to have the appropriate system option turned ON.
This enables the S-VOL to receive host I/O.
Restoring owner and non-owner paths 55