Sun Cluster Software Installation Guide for Solaris OS

ProcedureHow to Create a Disk Set

Perform this procedure to create disk sets.

  1. (Solaris 8 or Solaris 9) Determine whether, after you create the new disk sets, the cluster will have more than three disk sets.

    • If the cluster will have no more than three disk sets, skip to Step 9.

    • If the cluster will have four or more disk sets, proceed to Step 2 to prepare the cluster. You must perform this task whether you are installing disk sets for the first time or whether you are adding more disk sets to a fully configured cluster.

    • If the cluster runs on the Solaris 10 OS, Solaris Volume Manager automatically makes the necessary configuration changes. Skip to Step 9.

  2. On any node of the cluster, check the value of the md_nsets variable in the /kernel/drv/md.conf file.

  3. If the total number of disk sets in the cluster will be greater than the existing value of md_nsets minus one, increase the value of md_nsets to the desired value.

    The maximum permissible number of disk sets is one less than the configured value of md_nsets. The maximum possible value of md_nsets is 32, therefore the maximum permissible number of disk sets that you can create is 31.

  4. Ensure that the /kernel/drv/md.conf file is identical on each node of the cluster.

    Caution – Caution –

    Failure to follow this guideline can result in serious Solstice DiskSuite or Solaris Volume Manager errors and possible loss of data.

  5. If you made changes to the md.conf file on any node, perform the following steps to make those changes active.

    1. From one node, shut down the cluster.

      # scshutdown -g0 -y
    2. Reboot each node of the cluster.

      ok> boot
  6. On each node in the cluster, run the devfsadm(1M) command.

    You can run this command on all nodes in the cluster at the same time.

  7. From one node of the cluster, run the scgdevs(1M) command to update the global-devices namespace.

  8. On each node, verify that the scgdevs command has completed processing before you attempt to create any disk sets.

    The scgdevs command calls itself remotely on all nodes, even when the command is run from just one node. To determine whether the scgdevs command has completed processing, run the following command on each node of the cluster.

    % ps -ef | grep scgdevs
  9. Ensure that the disk set that you intend to create meets one of the following requirements.

    • If the disk set is configured with exactly two disk strings, the disk set must connect to exactly two nodes and use exactly two mediator hosts. These mediator hosts must be the same two hosts used for the disk set. See Configuring Dual-String Mediators for details on how to configure dual-string mediators.

    • If the disk set is configured with more than two disk strings, ensure that for any two disk strings S1 and S2, the sum of the number of drives on those strings exceeds the number of drives on the third string S3. Stated as a formula, the requirement is that count(S1) + count(S2) > count(S3).

  10. Ensure that the local state database replicas exist.

    For instructions, see How to Create State Database Replicas.

  11. Become superuser on the cluster node that will master the disk set.

  12. Create the disk set.

    The following command creates the disk set and registers the disk set as a Sun Cluster disk device group.

    # metaset -s setname -a -h node1 node2
    -s setname

    Specifies the disk set name


    Adds (creates) the disk set

    -h node1

    Specifies the name of the primary node to master the disk set


    Specifies the name of the secondary node to master the disk set

    Note –

    When you run the metaset command to configure a Solstice DiskSuite or Solaris Volume Manager device group on a cluster, the command designates one secondary node by default. You can change the desired number of secondary nodes in the device group by using the scsetup(1M) utility after the device group is created. Refer to Administering Disk Device Groups in Sun Cluster System Administration Guide for Solaris OS for more information about how to change the numsecondaries property.

  13. Verify the status of the new disk set.

    # metaset -s setname

Example 3–6 Creating a Disk Set

The following command creates two disk sets, dg-schost-1 and dg-schost-2, with the nodes phys-schost-1 and phys-schost-2 specified as the potential primaries.

# metaset -s dg-schost-1 -a -h phys-schost-1 phys-schost-2
# metaset -s dg-schost-2 -a -h phys-schost-1 phys-schost-2

Next Steps

Add drives to the disk set. Go to Adding Drives to a Disk Set.