Managing HP Serviceguard for Linux, Tenth Edition, September 2012

• Storing Volume Group Configuration Data (page 178)
• Setting up Disk Monitoring (page 179)
CAUTION: The minor numbers used by the LVM volume groups must be the same on
all cluster nodes. This means that if there are any non-shared volume groups in the cluster,
create the same number of them on all nodes, and create them before you define the
shared storage. If possible, avoid using private volume groups, especially LVM boot
volumes. Minor numbers increment with each logical volume, and mismatched numbers
of logical volumes between nodes can cause a failure of LVM (and boot, if you are using
an LVM boot volume).
NOTE: Except as noted in the sections that follow, you perform the LVM configuration
of shared storage on only one node. The disk partitions will be visible on other nodes
as soon as you reboot those nodes. After you’ve distributed the LVM configuration to all
the cluster nodes, you will be able to use LVM commands to switch volume groups between
nodes. (To avoid data corruption, a given volume group must be active on only one node
at a time).
For multipath information, see “Multipath for Storage ” (page 94).
Using the Generic Resources Disk Monitor
The Generic Resources Monitoring Service allows you to monitor the health of LVM disks.
If you are using LVM, you can configure disk monitoring to detect a failed mechanism
by using the disk monitor capabilities of the System Fault Management, available as a
separate product, and integrating it in Serviceguard by configuring generic resources
in packages. Monitoring can be set up to trigger a package failover or to report disk
failure events to Serviceguard by writing monitoring scripts, which can be configured as
a service in a package.
Monitoring scripts are user-written scripts that must contain the core logic to monitor a
resource and set the status of a generic resource using the generic resource commands,
cmgetresource(1m) and cmsetresource(1m).
For more information, see:
• HP-UX WBEM LVM Provider Datasheet at http://www.hp.com/go/hpux-core-docs
—> HP-UX 11i Volume Management (LVM/VxVM) Software
• “Using Generic Resources to Monitor Volume Groups” (page 98)
• “Monitoring Script for Generic Resources” (page 340)
• “Getting and Setting the Status/Value of a Simple/Extended Generic Resource”
(page 128) and the manpages
Displaying Disk Information
To display a list of configured disks, use the following command:
170 Building an HA Cluster Configuration