Managing Serviceguard Sixteenth Edition, March 2009

disk failure events to a Serviceguard, to another application, or by email. For more
information, refer to the manual Using High Availability Monitors (B5736-90074), available
at http://docs.hp.com -> High Availability -> Event Monitoring
Service and HA Monitors -> Installation and User’s Guide.
Monitoring VxVM and CVM Disks
The HP Serviceguard VxVM Volume Monitor provides a means for effective and
persistent monitoring of VxVM and CVM volumes. The Volume Monitor supports
Veritas Volume Manager versions 3.5, 4.1, and 5.0, as well as Veritas Cluster Volume
Manager (CVM) versions 3.5, 4.1, and 5.0.
You can configure the Volume Monitor (cmvxserviced) to run as a service in a package
that requires the monitored volume or volumes. When a monitored volume fails or
becomes inaccessible, the service will exit, causing the package to fail on the current
node. (The package’s failover behavior depends on its configured settings, as with any
other failover package.)
For example, the following service_cmd monitors two volumes at the default log level
0, with a default polling interval of 60 seconds, and prints all log messages to the console:
/usr/sbin/cmvxserviced /dev/vx/dsk/cvm_dg0/lvol1 /dev/vx/dsk/cvm_dg0/lvol2
For more information, see the cmvxserviced (1m) manpage. For more information
about configuring package services, see the parameter descriptions starting with
service_name (page 273).
Replacing Failed Disk Mechanisms
Mirroring provides data protection, but after a disk failure, the failed disk must be
replaced. With conventional disks, this is done by bringing down the cluster and
replacing the mechanism. With disk arrays and with special HA disk enclosures, it is
possible to replace a disk while the cluster stays up and the application remains online.
The process is described under “Replacing Disks” (page 364) .
Replacing Failed I/O Cards
Depending on the system configuration, it is possible to replace failed disk I/O cards
while the system remains online. The process is described under “Replacing I/O Cards”
(page 368).
Sample SCSI Disk Configurations
Figure 2-2 shows a two node cluster. Each node has one root disk which is mirrored
and one package for which it is the primary node. Resources have been allocated to
each node so that each node may adopt the package from the other node. Each package
has one disk volume group assigned to it and the logical volumes in that volume group
are mirrored. Please note that Package A’s disk and the mirror of Package B’s disk are
on one interface while Package B’s disk and the mirror of Package A’s disk are on a
46 Understanding Serviceguard Hardware Configurations