HP XP Cluster Extension Software Administrator Guide
Recovery sequence
To recover from a server or Continuous Access link failure:
1. Start the RAID Manager instances on both local and remote servers:
set HORCMINST=instance_number
HORCMSTART instance_number
2. Gather general pair status information:
pairdisplay –g device_group
3. Display the pair status information after a failed swap-takeover (the S-VOL state is SSWS):
pairdisplay –g device_group –fc
4. To recover from these states, invoke the following command from the S-VOL side:
pairresync –swaps –c 15 –g device_group
If the pair needs to be used on the old primary side, the following commands must be invoked
from the primary side:
pairresync –swapp –c 15 –g device_group
horctakeover –g device_group
5. Display the pair status information after a P-VOL takeover (local P-VOL PSUS; remote S-VOL
PAIR):
pairdisplay –g device_group –fc
To recover from these states, invoke the following command from the P-VOL side:
pairresync –c 15 –g device_group
CAUTION:
The application must be shut down and the file systems unmounted before a fenced disk in
fence level DATA can be set in read/write mode again. After the P-VOL takeover, the file
system must be checked before it can be mounted. Any other recovery procedure could lead
to unrecoverable file systems.
• If a horctakeover command results in S-VOL, or P-VOL becomes SMPL and none of
the disks in the device/copy group has been written to, you can recover from the situation
by splitting the remaining P-VOL or S-VOL to SMPL:
pairsplit [[-S] | [-R]] -g device_group
After splitting the pair, the pair can be re-created without copying its content using:
paircreate -nocopy –c 15 -f fence_level -g device_group -v [[r] |
[l]]
• If a horctakeover command results in S-VOL, or P-VOL becomes SMPL and data was
written to one of the disks in the device/copy group, you can recover from the situation
by splitting the remaining P-VOL or S-VOL to SMPL:
pairsplit [[-S] | [-R]] -g device_group
After being split, the pair can be re-created with a full copy using:
paircreate –c 15 -f fence_level -g device_group -v [[r] | [l]]
To ensure that a certain pair state has been established, invoke the event wait command:
pairevtwait -g device_group -t time_to_wait -s pair_state
46 XP Cluster Extension recovery procedures