Veritas Volume Manager 5.0 Administrator's Guide (September 2006)

439Using Storage Expert
Identifying configuration problems using Storage Expert
Identifying configuration problems using Storage Expert
Storage Expert provides a large number of rules that help you to diagnose configuration
issues that might cause problems for your storage environment. Each rule describes the
issues involved, and suggests remedial actions.
The rules help you to diagnose problems in the following categories:
■ Recovery time
■ Disk groups
■ Disk striping
■ Disk sparing and relocation management
■ Hardware failures
■ Rootability
■ System name
A full list of Storage Expert rules, listed in numerical order, can be found in “Rule
definitions and attributes” on page 445.
Recovery time
Several “best practice” rules enable you to check that your storage configuration has the
resilience to withstand a disk failure or a system failure.
Checking for multiple RAID-5 logs on a physical disk
(vxse_disklog)
To check whether more than one RAID-5 log exists on the same physical disk, run rule
vxse_disklog.
RAID-5 log mirrors for the same physical volume should be located on separate physical
disks to ensure redundancy. More than one RAID-5 log on a disk also makes the recovery
process longer and more complicated.
Checking for large mirror volumes without a dirty region log
(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.