Managing Serviceguard Eighteenth Edition, September 2010

NOTE: 4.1 and later versions of Veritas Volume Manager (VxVM) and Dynamic
Multipathing (DMP) from Symantec are supported on HP-UX 11i v3, but do not provide
multipathing and load balancing; DMP acts as a pass-through driver, allowing
multipathing and load balancing to be controlled by the HP-UX I/O subsystem instead.
For more information about multipathing in HP-UX 11i v3, see the white paper HP-UX
11i v3 Native Multi-Pathing for Mass Storage, and the Logical Volume Management volume
of the HP-UX System Administrator’s Guide at the address given in the preface to this
manual. See also “About Device File Names (Device Special Files)” (page 106).
Monitoring LVM Disks Through Event Monitoring Service
If you are using LVM, you can configure disk monitoring to detect a failed mechanism
by using the disk monitor capabilities of the EMS HA Monitors, available as a separate
product . Monitoring can be set up to trigger a package failover or to report disk failure
events to a Serviceguard, to another application, or by email. For more information,
see “Using EMS to Monitor Volume Groups” (page 132).
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 4.1 and 5.0, as well as Veritas Cluster Volume
Manager (CVM) versions 4.1and 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 299).
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 402) .
46 Understanding Serviceguard Hardware Configurations