How to Create an md.tab File

Create an /etc/lvm/md.tab file on each node in the cluster. Use the md.tab file to define Solaris Volume Manager volumes for the disk sets that you created.

If you are using local volumes, ensure that local volume names are distinct from the device-ID names that are used to form disk sets. For example, if the device-ID name /dev/did/dsk/d3 is used in a disk set, do not use the name /dev/md/dsk/d3 for a local volume. This requirement does not apply to shared volumes, which use the naming convention /dev/md/setname/{r}dsk/d#.

1. Become superuser.

2. List the DID mappings for reference when you create your md.tab file.

   Use the full DID device names in the md.tab file in place of the lower-level device names (cN tXdY). The DID device name takes the form /dev/did/rdsk/dN.

   phys-schost# cldevice show | grep Device

   === DID Device Instances === DID Device Name: /dev/did/rdsk/d1 Full Device Path: phys-schost-1:/dev/rdsk/c0t0d0 DID Device Name: /dev/did/rdsk/d2 Full Device Path: phys-schost-1:/dev/rdsk/c0t6d0 DID Device Name: /dev/did/rdsk/d3 Full Device Path: phys-schost-1:/dev/rdsk/c1t1d0 Full Device Path: phys-schost-2:/dev/rdsk/c1t1d0 …

3. Create an /etc/lvm/md.tab file and edit it with your preferred text editor.

   ---

   Note –

   If you have existing data on the drives that will be used for the submirrors, you must back up the data before volume setup. Then restore the data onto the mirror.

   ---

   To avoid possible confusion between local volumes on different nodes in a cluster environment, use a naming scheme that makes each local volume name unique throughout the cluster. For example, for node 1 choose names from d100 to d199. And for node 2 use d200 to d299.

   See your Solaris Volume Manager documentation and the md.tab(4) man page for details about how to create an md.tab file.

Example 4–8 Sample md.tab File

The following sample md.tab file defines the disk set that is named dg-schost-1. The ordering of lines in the md.tab file is not important.

dg-schost-1/d0 -m dg-schost-1/d10 dg-schost-1/d20
    dg-schost-1/d10 1 1 /dev/did/rdsk/d1s0
    dg-schost-1/d20 1 1 /dev/did/rdsk/d2s0

The sample md.tab file is constructed as follows.

1. The first line defines the device d0 as a mirror of volumes d10 and d20. The -m signifies that this device is a mirror device.

   dg-schost-1/d0 -m dg-schost-1/d0 dg-schost-1/d20

2. The second line defines volume d10, the first submirror of d0, as a one-way stripe.

   dg-schost-1/d10 1 1 /dev/did/rdsk/d1s0

3. The third line defines volume d20, the second submirror of d0, as a one-way stripe.

   dg-schost-1/d20 1 1 /dev/did/rdsk/d2s0

Next Steps

Activate the volumes that are defined in the md.tab files. Go to How to Activate Volumes.