Managing Serviceguard A.11.20, March 2013

When designing a storage configuration using CVM or VxVM disk groups, consider the following:
• CVM disk groups are created after the cluster is configured, whereas VxVM disk groups may
be created before cluster configuration if desired.
• High availability applications, services, and data should be placed in separate disk groups
from non-high availability applications, services, and data.
• You must not group two different high availability applications, services, or data, whose control
needs to be transferred independently, onto the same disk group.
• Your HP-UX root disk can belong to an LVM or VxVM volume group that is not shared among
cluster nodes.
• A cluster lock disk must be configured into an LVM volume group; you cannot use a VxVM or
CVM disk group. (See “Cluster Lock Planning” (page 103) for information about cluster lock
options.)
• VxVM disk group names should not be entered into the cluster configuration file. These names
are not inserted into the cluster configuration file by cmquerycl.
CVM and VxVM Worksheet
You may find a worksheet such as the following useful to help you organize and record your
specific physical disk configuration. This worksheet is an example; blank worksheets are in
Appendix E (page 375).
=========================================================================
Disk Group Name: ______dg01_____________________
Disk Name: _____________________c1t2d0__________________________
Disk Name: _____________________c2t2d0__________________________
Disk Name: _____________________c3t2d0__________________________
Disk Name: _____________________________________________________
CFS DG Package Name: ___________SG-CFS-DG_1_____
CFS Volume, MP, and MP Pkg: _logdata_/mnt/lvol1_ SG-CFS-MP_1______
CFS Volume, MP, and MP Pkg: ______________________________________
Disk Group Name: ______dg02______________________
Disk Name: _____________________c1t3d0__________________________
Disk Name: _____________________c2t3d0__________________________
Disk Name: _____________________c3t3d0__________________________
CFS DG Package Name: ___________SG-CFS-DG_2_____
CFS Volume, MP, and MP Pkg: _hrdata__/mnt/lvol4_ SG-CFS-MP_2____
CFS Volume, MP, and MP Pkg: ____________________________________
Cluster Configuration Planning
A cluster should be designed to provide the quickest possible recovery from failures. The actual
time required to recover from a failure depends on several factors:
• The value of the cluster MEMBER_TIMEOUT.
See MEMBER_TIMEOUT under “Cluster Configuration Parameters ” (page 114) for
recommendations.
• The availability of raw disk access. Applications that use raw disk access should be designed
with crash recovery services.
• The application and database recovery time. They should be designed for the shortest recovery
time.
In addition, you must provide consistency across the cluster so that:
• User names are the same on all nodes.
• UIDs are the same on all nodes.
108 Planning and Documenting an HA Cluster