Veritas Volume Manager 4.1 Administrator's Guide (HP-UX 11i v3, February 2007)

Chapter 14, Using VERITAS Storage Expert
Identifying Configuration Problems Using Storage Expert
387
Checking for Large Mirror Volumes Without a DRL (vxse_drl1)
To check whether large mirror volumes (larger than 1GB) have an associated dirty region
log (DRL), run rule vxse_drl1.
Creating a DRL speeds recovery of mirrored volumes after a system crash. A DRL tracks
those regions that have changed and uses the tracking information to recover only those
portions of the volume that need to be recovered. Without a DRL, recovery is
accomplished by copying the full contents of the volume between its mirrors. This process
is lengthy and I/O intensive.
For information on adding a DRL log to a mirrored volume, see “Preparing a Volume for
DRL and Instant Snapshots” on page 235.
Checking for Large Mirrored Volumes Without a Mirrored DRL
(vxse_drl2)
To check whether a large mirrored volume has a mirrored DRL log, run rule vxse_drl2.
Mirroring the DRL log provides added protection in the event of a disk failure.
For information on adding a mirror to a DRL log, see “Preparing a Volume for DRL and
Instant Snapshots” on page 235.
Checking for RAID-5 Volumes Without a RAID-5 Log (vxse_raid5log1)
To check whether a RAID-5 volume has an associated RAID-5 log, run rule
vxse_raid5log1.
In the event of both a system failure and a failure of a disk in a RAID-5 volume, data that
is not involved in an active write could be lost or corrupted if there is no RAID-5 log.
For information about adding a RAID-5 log to a RAID-5 volume, see “Adding a RAID-5
Log” on page 243.
Checking Minimum and Maximum RAID-5 Log Sizes (vxse_raid5log2)
To check that the size of RAID-5 logs falls within the minimum and maximum
recommended sizes, run rule vxse_raid5log2.
The recommended minimum and maximum sizes are 64MB and 1GB respectively. If
vxse_raid5log2 reports that the size of the log is outside these boundaries, adjust the
size by replacing the log.