How to Set the Number of Metadevice Names and Disksets

If you used SunPlex Manager to install Solstice DiskSuite software, do not perform this procedure. Instead, go to "Mirroring the Root Disk".

This procedure describes how to calculate the quantity of metadevice names needed for your configuration, and how to modify the /kernel/drv/md.conf file.

The default number of metadevice names per diskset is 128, but many configurations need more than the default. Increase this number before you implement a configuration, to save administration time later.

1. Calculate the largest metadevice name you need for any diskset in the cluster.

   Each diskset can have a maximum of 8192 metadevice names. You will supply this calculated value for the nmd field.

   1. Calculate the quantity of metadevice names you need for each diskset.

      If you use local metadevices, ensure that each local metadevice name is unique throughout the cluster and does not use the same name as any device ID (DID) in the cluster.

      ---

      Tip -

      Choose a range of numbers to use exclusively for DID names and a range for each node to use exclusively for its local metadevice names. For example, DIDs would use names in the range from d1 to d1000, local metadevices on node 1 would use names in the range from d1100 to d1199, local metadevices on node 2 would use d1200 to d1299, and so on.

      ---

   2. Determine the largest of the metadevice names to be used in any diskset.

      The quantity of metadevice names to set is based on the metadevice name value rather than on the actual quantity. For example, if your metadevice names range from d950 to d1000, Solstice DiskSuite software requires 1000 names, not 50.

2. Calculate the total expected number of disksets in the cluster, then add one for private disk management.

   The cluster can have a maximum of 32 disksets. The default number of disksets is 4. You will supply this calculated value for the md_nsets field.

3. On each node, edit the /kernel/drv/md.conf file.

   ---

   Caution -

   All cluster nodes (or cluster pairs in the cluster-pair topology) must have identical /kernel/drv/md.conf files, regardless of the number of disksets served by each node. Failure to follow this guideline can result in serious Solstice DiskSuite errors and possible loss of data.

   ---

   1. If the calculated quantity of metadevice names exceeds 128, set the nmd field to the quantity calculated in Step 1.

   2. Set the md_nsets field to the quantity calculated in Step 2.

4. On each node, perform a reconfiguration reboot.

   # touch /reconfigure # shutdown -g0 -y -i6

   Changes to the /kernel/drv/md.conf file become operative after you perform a reconfiguration reboot.

5. Create local replicas.

   Go to "How to Create Metadevice State Database Replicas".