Administering Disk Groups

For VxVM, it is most convenient to create and populate disk groups from the active node that is the default master of the particular disk group. In an N+1 configuration, each of these default master nodes shares multihost disk connectivity with only one other node in the cluster, the hot-standby node. By using these nodes to populate the disk groups, you avoid the risk of generating improperly configured groups.

Creating a Disk Group (VxVM)

You can use either the vxdiskadm menus or the graphical user interface to create a new disk group. Alternately, you can use the command-line utility vxdg init.

Once the disk groups have been created and populated, each one should be deported by using the vxdg deport command. Then, each group should be imported onto the hot-standby node by using the -t option. The -t option is important, as it prevents the import from persisting across the next boot. All VxVM plexes and volumes should be created, and volumes started, before continuing.

Moving a Disk to a Different Disk Group (VxVM)

Use the following procedure to move a disk to a different disk group.

How to Move a Disk to a Different Disk Group (VxVM)

To move a disk between disk groups, remove the disk from one disk group and add it to the other.

This example moves the physical disk c1t0d1 from disk group acct to disk group log_node1 by using command-line utilities.

1. Use the vxprint(1M) command to determine if the disk is in use.

   # vxprint -g acct TY NAME ASSOC KSTATE LENGTH PLOFFS STATE TUTIL0 PUTIL0 dg acct acct - - - - - - dm c1t0d0 c1t0d0s2 - 2050272 - - - - dm c1t0d1 c1t0d1s2 - 2050272 - - - - dm c2t0d0 c2t0d0s2 - 2050272 - - - - dm c2t0d1 c2t0d1s2 - 2050272 - - - - v newvol gen ENABLED 204800 - ACTIVE - - pl newvol-01 newvol ENABLED 205632 - ACTIVE - - sd c1t0d1-01 newvol-01 ENABLED 205632 0 - - - pl newvol-02 newvol ENABLED 205632 - ACTIVE - - sd c2t0d1-01 newvol-02 ENABLED 205632 0 - - - v vol01 gen ENABLED 1024000 - ACTIVE - - pl vol01-01 vol01 ENABLED 1024128 - ACTIVE - - sd c1t0d0-01 vol01-01 ENABLED 1024128 0 - - - pl vol01-02 vol01 ENABLED 1024128 - ACTIVE - - sd c2t0d0-01 vol01-02 ENABLED 1024128 0 - - -

2. Use the vxedit(1M) command to remove the volume to free up the c1t0d1 disk.

   You must run the vxedit command from the node mastering the shared disk group.

   # vxedit -g acct -fr rm newvol

   The -f option forces an operation. The -r option makes the operation recursive.

3. Remove the c1t0d1 disk from the acct disk group.

   You must run the vxdg command from the node mastering the shared disk group.

   # vxdg -g acct rmdisk c1t0d1

4. Add the c1t0d1 disk to the log_node1 disk group.

   # vxdg -g log_node1 adddisk c1t0d1

   ---

   Caution -

   This procedure does not save the configuration or data on the disk.

   ---

   This is the acct disk group after c1t0d1 is removed.

   # vxprint -g acct TY NAME ASSOC KSTATE LENGTH PLOFFS STATE TUTIL0 PUTIL0 dg acct acct - - - - - - dm c1t0d0 c1t0d0s2 - 2050272 - - - - dm c2t0d0 c2t0d0s2 - 2050272 - - - - dm c2t0d1 c2t0d1s2 - 2050272 - - - - v vol01 gen ENABLED 1024000 - ACTIVE - - pl vol01-01 vol01 ENABLED 1024128 - ACTIVE - - sd c1t0d0-01 vol01-01 ENABLED 1024128 0 - - - pl vol01-02 vol01 ENABLED 1024128 - ACTIVE - - sd c2t0d0-01 vol01-02 ENABLED 1024128 0 - - -

   This is the log_node1 disk group after c1t0d1 is added.

   # vxprint -g log_node1 TY NAME ASSOC KSTATE LENGTH PLOFFS STATE TUTIL0 PUTIL0 dg log_node1 log_node1 - - - - - - dm c1t0d1 c1t0d1s2 - 2050272 - - - - dm c1t3d0 c1t3d0s2 - 2050272 - - - - dm c2t3d0 c2t3d0s2 - 2050272 - - - - #

   To change permissions or ownership of volumes, you must use the vxedit command.

   ---

   Caution -

   Do not use chmod or chgrp. The permissions and ownership set by chmod or chgrp are automatically reset to root during a reboot.

   ---

   Here is an example of the permissions and ownership of the volumes vol01 and vol02 in the /dev/vx/rdsk directory before a change.

   # ls -l crw------- 1 root root nnn,nnnnn date time vol01 crw------- 1 root root nnn,nnnnn date time vol02 ...

   This an example for changing the permissions and ownership for vol01.

   # vxedit -g group_name set mode=755 user=oracle vol01

   After the edit, note how the permissions and ownership have changed.

   # ls -l crwxr-xr-x 1 oracle root nnn,nnnnn date time vol01 crw------- 1 root root nnn,nnnnn date time vol02 ...