HP XP P9500 Storage - Manual (Page 53)

continues during recovery procedures if the MCU is receiving the I/O, but stops if the RCU is
receiving it.
•
If you can recover the external storage system where the quorum disk is located without deleting
any information in the disk, then the pairs can be resynchronized, and the quorum disk does
not need to be deleted and replaced. In this case, follow the workflow diagram in
“Recovery
using resynchronization” (page 50) .
Recovery after power outage
When the primary or secondary system is powered off and backup batteries are discharged,
shared memory in the affected system is initialized. This results in differential data being lost. The
following sections describe the recovery procedures for this condition, according to the system that
is powered off: primary or secondary.
Recovering the primary system
When the primary system's memory has been initialized, recover the ESAM system according to
one of the following:
•
Whether S-VOL is receiving host updates following failover.
•
Whether host updates are stopped completely.
Procedure 35 To recover the primary system when failover has switched host updates to the S-VOL:
1. Verify that the S-VOL has the latest data and is being updated. Open the Pair Operation
window on the secondary system and check that the VOL Access column displays Access (Lock).
2. Stop I/O from the host.
3. On the secondary system, release the ESAM pair.
4. On the secondary system, delete the quorum disk ID.
5. On the secondary system, create a Continuous Access Synchronous pair. The data flow is
from secondary to primary sites.
6. Format the quorum disk.
7. On the primary system, register the ESAM secondary system to the primary system. See
“Configuring primary and secondary systems ” (page 23) .
8. If using RAID Manager, continue with this step. If using Remote Web Console, skip to the next
step.
1.
When the Continuous Access Synchronous operation is completed, execute the
horctakeover
command on the primary system S-VOL to reverse the P-VOL and S-VOL.
2. On the primary and secondary systems, add the quorum disk. See “Adding a quorum
disk ID ” (page 25) .
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.
9. If using Remote Web Console, continue as follows:
1.
On the secondary system, release the Continuous Access Synchronous pair.
2. On the primary and secondary systems, add the quorum disk.
3. On the primary system, create the ESAM pair.
10. On both the primary and secondary systems, make sure that the pair volume's Type field is
ESAM.
11. Using the multipath software. vary the owner and non-owner paths online.
12. Restart host I/O.
Recovery after power outage 53