HP P6000 Continuous Access Implementation Guide (T3680-96431, August 2012)

Your first indication that a disk group has become inoperative may be icons like those shown in
“HP P6000 Replication Solutions Manager display icons” (page 114), except that the destination
disk group status is Unknown.
NOTE: When you delete DR groups to recover from a disk group hardware failure, you do not
have disaster tolerance until you re-create the DR groups and they have completed normalization.
If you create mirrorclones of the destination virtual disks in the DR group and regularly update
them, you will have some protection from a disaster but the data will be as old as the last mirrorclone
resynchronization.
Procedure:
Perform this procedure when a disk group hardware failure occurs on the destination array.
NOTE: Because the source data is intact, there is no data loss in this scenario.
1. Disable failsafe mode, if set.
2. Use HP P6000 Command View to navigate to the failed disk group.
A list of failed virtual disks and DR groups is displayed. See Figure 57 (page 115).
3. Click Start Resolution Process.
After a confirmation message, a list of failed DR groups appears.
4. Unpresent the affected destination virtual disk members: one at a time, select an affected
virtual disk, select the Presentation tab on the Vdisk Properties window; and then click
Unpresent.
Repeat this step for each affected destination virtual disk member.
5. Select an affected DR group, and then click Delete.
Deleting a DR group removes the relationship between the virtual disk members; it does not
delete data from the virtual disks.
6. Repeat Step 5 for each affected DR group.
7. Navigate to the disk group and click Finish to resolve the disk group hardware failure.
8. On the source array, delete the DR group associated with the DR groups deleted in Step 5.
9. (Optional) Repair your hard drives and re-create your disk group on the destination array.
For more information, see the user guide for your array model and the HP P6000 Command
View User Guide.
10. Refresh the source array and re-create the DR groups.
11. On the destination array, present the destination virtual disks.
Protecting data from a site failure
When the destination array is unavailable and both controllers on the source array are restarted,
host presentation of source virtual disks is blocked and remains blocked until the destination array
becomes available (and can communicate with the source array) or until you suspend the DR group.
It is possible to disable this feature on newer versions on controller software. For more information,
see “Failsafe on Link-down/Power-up” (page 11).
Blocking host presentation protects data during a site failure, where the potential exists for both
sides of the remote replication connection to be presented to hosts simultaneously. Blocking also
protects cluster members from detecting or accessing two copies of the same data. It also protects
boot from SAN (BFS) servers from two hosts booting against the same boot image.
You can use HP P6000 Replication Solutions Manager or HP P6000 Command View to determine
if host presentation is blocked.
116 Failover and recovery