Using EMS HA Monitors

Chapter 2 41
Monitoring Disk Resources
Rules for Using the EMS Disk Monitor with MC/ServiceGuard
The pv_summary is calculated based on the compiled results of SCSI inquiries to all
physical volumes in a volume group. To help you determine the best way to
configure your disks for monitoring, here are the assumptions made when
calculating pv_summary:
• PVGs (physical volume groups) are set up to be bus-specific sides of a mirror or
redundant links and have an equal number of physical volumes.
• All logical volumes within a volume group are mirrored in the same way: all
2-way or all 3-way mirroring.
• A package depends on all logical volumes in the volume group.
• The SCSI inquiry will retry on devices that are BUSY. BUSY devices are not
considered UP when calculating pv_summary.
These rules apply when creating PVGs, if they are not followed, pv_summary will
not be available for monitoring:
• If PVGs are used, all physical volumes in a volume group must be in a PVG.
• All PVGs in a volume group must have the same number of physical volumes.