Using High Availability Monitors (June 2003)

Monitoring Disk Resources
HA Disk Monitor Reference
Chapter 232
pv_pvlinks and pv_summary supplement lv_summary by giving status
on the accessibility of volume groups (both active and inactive) and
logical volumes.
To pinpoint a failure of a particular disk, bus, or I/O card, you need to use
the HA Disk Monitor alerts in conjunction with standard troubleshooting
methods: reading log files and inspecting the actual devices. The HA
Disk Monitor uses the data in /etc/lvmtab to see what is available for
monitoring, and /etc/lvmtab does not distinguish between physical
volumes and physical volume links, so you need to investigate to detect
whether a disk, bus, or I/O card has failed.
Table 2-2 lists how conditions compare in logical operations. You specify
the logical operation in the monitor request parameters portion of the
monitor request. For example, to create a request that alerts you when
the condition isBUSY, you would specify greater than or equal to2 (>=2).
While configuring requests from the SAM interface, a wildcard (*) can be
used in placeof deviceName to monitor allphysical volumes and physical
volume links in a volume group.
Logical Volume Summary
The logical volume summary describes how accessible the data is in all
logical volumes in an active volume group. Sometimes the physical
connection may be working, but the application cannotread or write data
on the disk. The HA Disk Monitor determines I/O activity by querying
LVM, and marks a logical volume as DOWN if a portion of its data is
unavailable.
Table 2-2 Interpreting Physical Volume and Physical Volume Link Status
Resource Name: /vg/ vgName /pv_pvlink/status/ deviceName
Condition Value Interpretation
UP 1 SCSI inquiry was successful.
BUSY 2 SCSI inquiry returned with DEVICE BUSY. The HA
Disk Monitor will try 3 times to see if it gets either
an UP or DOWN result before marking a device BUSY.
DOWN 3 SCSI inquiry failed. The bus and/or the disk is not
accessible.