HP XP Racks - Manual (Page 180)

Notes on Enabling Both Primary and Secondary Volumes to Be
Viewed From the Same Server
To enable both primary and secondary volumes to be viewed from the
same server, operate the disks according to the following steps:
1
.
Create a pair of the primary volume and the secondary volume
(paircreate).
2
.
Split the pair (pairsplit).
3
.
Enable the secondary volume to be recognized as a volume group
(recreatevg).
When you execute the recreatevg command, characteristics of the
volume group will be initialized. Therefore, change the characteristics of
the volume group (chvg) as necessary.
4
.
Access the primary volume and the secondary volume.
5
.
Export the volume group, and then delete the volume information
(exportvg).
6
.
Re-synchronize the volume pair (pairresync).
7
.
If there are several pairs of primary and secondary volumes, repeat the
above steps for each pair (step 2 to step 6).
Notes on an LVM Mirror Configuration
When an error (such as one that might occur in a LVM mirror configuration) is
detected and I/O access for a path in the Online(E) status continues,
detection of errors will continue. When the -i parameter of the utility for
setting the HDLM execution environment ODM (dlmodmset) is set to on, I/O
access is suppressed until troubleshooting measures are taken. This can
shorten the time needed to deal with the problem.
However, when this parameter is set to on, I/O access to the path in the
Online(E) status will be suppressed, so I/O success will not automatically
change the path to the Online status. To recover the path, use an online
command or the auto failback function.
For details about the dlmodmset utility, see dlmodmset Utility for Setting the
HDLM Execution Environment ODM on page 7-22 .
Notes on When the OS Functionality in Not Available in a Boot Disk
Environment
When both of the following conditions exist, the reservation for the LU used
for the boot disk is not canceled:
• The reservation policy of the boot disk has been set to PR_exclusive.
• The OS cannot start because OS functionality is not available due to a
problem such as an error occurring in all of the boot disk's paths.
4-4
HDLM Operation
Hitachi Dynamic Link Manager (for AIX) User Guide