Veritas Storage Foundation 5.0.1 Cluster File System Administrator's Guide Extracts for the HP Serviceguard Storage Management Suite on HP-UX 11i v3

cluster environment. A local mount cannot be remounted in shared mode and a shared mount
cannot be remounted in local mode. File systems in a cluster can be mounted with different
read-write options. These are called asymmetric mounts.
Cluster File System Primary and Cluster File System Secondary
Both primary and secondary nodes handle metadata intent logging for a cluster file system. The
first node of a cluster file system to mount is called the primary node - the other nodes are called
secondary nodes. If a primary node fails, an internal election process determines which of the
secondaries becomes the primary file system.
Use the following command to determine which node is primary:
# fsclustadm –v showprimary mount_point
Use the following command to designate a primary node:
# fsclustadm –v setprimary mount_point
Asymmetric Mounts
Asymmetric mounts allow shared file systems to be mounted with different read/write capabilities.
One node in the cluster can mount read-write, while other nodes mount read-only.
You can specify the cluster read-write (crw) option when you first mount the file system. The
first column in the following table shows the mode in which the primary is mounted. The “X”
marks indicate the modes available to secondary nodes in the cluster.
See the mount_vxfs(1M) manual page for more information.
Table 3-1 Primary and Secondary Mount Options
Secondary: ro, crwSecondary: rwSecondary: ro
XPrimary: ro
XXPrimary: rw
XXPrimary: ro, crw
Mounting the primary node with only the -o cluster,ro option prevents the secondary
nodes from mounting in the read-write mode. Note that mounting the primary node with the
rw option implies read-write capability throughout the cluster.
Cluster File System Administration
This section describes some of the major aspects of cluster file system administration and the
ways that it differs from single-host VxFS administration.
Cluster File System Commands
The CFS commands are:
• cfscluster—cluster configuration command
• cfsmntadm—adds, deletes, modifies, and sets policy on cluster mounted file systems
• cfsdgadm—adds or deletes shared disk groups to/from a cluster configuration
• cfsmount/cfsumount—mounts/unmounts a cluster file system on a shared volume
Cluster File System Administration 25