Preparing NFS Services

Your configuration may include disks on the shared bus that support NFS. File systems exported by NFS can be configured on disk partitions or on VERITAS Volume Manager volumes. An example disk partition name is /dev/dsk/c1t12d0. An example volume name is /dev/vx/dsk/shareddg/vol3. Each name represents the block device on which the file system is to be mounted.

Major and Minor Numbers

Block devices providing NFS service must have the same major and minor numbers on each system. Major and minor numbers are used by HP-UX to identify the logical partition or disk slice. NFS also uses them to identify the exported file system. Major and minor numbers must be checked to ensure that the NFS identity for the file system is the same when exported from each system.

• For LVM, major numbers are fixed at 64, and minor numbers are assigned when the volumes are created. The assigned numbers must be the same on all systems.
• For VxVM, major numbers are fixed at 99, and minor numbers are assigned when the volumes are created. The assigned numbers must be the same on all systems.

The rest of this section deals with checking and changing minor numbers in the case there are disks running file systems not under any volume manager control. In this example case, the major number is fixed at 31.

Checking Major and Minor Numbers

1. Use the following command on all systems exporting an NFS file system. This command displays the major and minor numbers for the block device. For VxVM volumes, you must first import the associated shared disk group on each system.
    # ls -lL block_device

   The variable block_device refers to a partition on which a file system is mounted for export via NFS. Use this command on each NFS file system. For example, type:

   
    # ls -lL /dev/dsk/c1t15d0

   Output on System A resembles:

   
    brw-r----- 1 bin sys 31 0x039000 Dec 3 11:50 /dev/dsk/c1t15d0

   Output on System B resembles:

   
    brw-r----- 1 bin sys 31 0x039000 Dec 3 12:05 /dev/dsk/c1t15d0

   The major numbers, 31, and the minor numbers, 0x039000, match.

2. If the minor numbers do not match, refer to Reconciling Minor Numbers for NFS Shared Disks.
3. Check major and minor numbers on each block device used for NFS.