HP-UX HB v13.00 Ch-15 - Serviceguard

HP-UX Handbook – Rev 13.00 Page 94 (of 108)
Chapter 15 Serviceguard
October 29, 2013
cmquerycl -q, cmapplyconf -C, and cmcheckconf -C
• If there is a node or network failure that creates a 50-50 membership split, the quorum
server will not be available as a tie-breaker, and the cluster will fail
Types of Volume Managers
Serviceguard allows a choice of volume managers for data storage:
• HP-UX Logical Volume Manager (LVM) and (optionally)
Mirrordisk/UX
• VERITAS Volume Manager for HP-UX (VxVM)
• VERITAS Cluster Volume Manager for HP-UX (CVM)
Supported Volume Managers
For a list of supported volume managers on HPUX and Serviceguard versions, refer to the HP
Serviceguard Solutions Storage Support Matrix at http://www.hp.com/go/sgstoragesupport.
HP-UX Logical Volume Manager
Logical Volume Manager (LVM) is the default storage management product on HP-UX.
The Serviceguard cluster lock disk is configured using a disk configured in an LVM volume
group. LVM continues to be supported on HP-UX single systems and on Serviceguard clusters.
LVM VG activation modes
Volume groups that are private to a particular server activate using the standard activation mode
using ‘vgchange –a y <vg>’.
In order to protect the data on volume groups that may be shuffled amongst Serviceguard nodes
when a failover package (one that runs only on one node at a time) is moved, exclusive activation
mode, implemented using ‘vgchange –a e <vg>’ is required. For those volume groups activated
on multiple systems simultaneously to implement SGeRAC raw-data volume access, shared
activation mode is implemented using ‘vgchange –a s <vg>’.
To set activation modes:
Standard: vgchange –c n <vg>
Exclusive: cmapplyconf where VG is identified in the cluster ASCII file with a
VOLUME_GROUP parameter or vgchange –c y <vg> (NOTE: cmcld and cmlvmd must be
running). The latter method is sometimes used if cmapplyconf rejects the disk type.
Shared: With the cluster running: ‘vgchange –c y –S y <vg>’.
Co-mounting file systems
Logical volumes whose volume groups are activated in standard mode or shared mode cannot be
mounted on multiple systems concurrently without risking a system panic because HPUX LVM
provides no means of informing other systems of in-memory file system inode table
modifications. Serviceguard with VxVM-based CFS is the only supported means to
concurrently mount a file system to multiple servers.
VERITAS Volume Manager (VxVM)
VxVM provides us the basic functionality to manage the physical disk space in order to create