Using EMS HA Monitors

34 Chapter 2

Monitoring Disk Resources

Disk Monitor Reference

Physical Volume Summary

The pv_summary is a summary status of all physical volumes in a volume group.

This status is based on the compiled results of SCSI inquiries to all physical

volumes in a volume group; see “Physical Volume and Physical Volume Link

Status” on page 36.

If you have conﬁgured package dependencies in MC/ServiceGuard, this resource is

used to determine package failover based on access to physical disks. (See Chapter 1

for information on conﬁguring MC/ServiceGuard package dependencies.) If you are

using the disk monitor with MC/ServiceGuard, it is important that you conﬁgure

physical volume groups (PVGs) to give you the most accurate pv_summary for

MC/ServiceGuard package failover. See “Rules for Using the EMS Disk Monitor

with MC/ServiceGuard” on page 40.

The value in Table 2-1 is used by the disk monitor to determine how conditions

compare in logical operations. For example, you may create a request that alerts you

when the condition is greater than or equal to SUSPECT. The numeric value allows

you to tell which conditions qualify.

Table 2-1 Interpreting Physical Volume Summary

Resource Name /vg/vgName/pv_summary

Condition Value Interpretation

UP 1 All physical volumes containing data are accessible.

PVG_UP 2 At least 1 PV has failed; all data is accessible. If more than 1 is down and the

failed PVs are from the same PVG, all data is still accessible.

This condition can only occur in mirrored set or if PV links in PVGs.

SUSPECT 3 Two or more physical volumes from different PVGs are unavailable; the disk

monitor cannot conclude that all data is available.

For example, on a 2-way mirrored system, if a physical volume fails on each

side of the mirror, data may be available if the failed volumes are holding

different data. But data may be unavailable if the failed volumes hold the

same data. Because the disk monitor only knows disks have failed, and not

what data is on the disks, it marks the volume group SUSPECT.

DOWN 4 Some data missing or no data accessible.