Sun Cluster System Administration Guide for Solaris OS

ProcedureHow to Create More Than Three Disk Sets in a Cluster

If you intend to create more than three disk sets in the cluster, perform the following steps before you create the disk sets. Follow these steps if you are installing disk sets for the first time or if you are adding more disk sets to a fully configured cluster.

  1. Ensure that the value of the md_nsets variable is high enough. The value should accommodate the total number of disk sets you intend to create in the cluster.

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

    2. If the 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 on each node.

      The maximum permissible number of disk sets is the value of md_nsets minus one. The maximum possible value of md_nsets is 32.

    3. 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/Solaris Volume Manager errors and possible loss of data.

    4. From one node, shut down the cluster.

      # scshutdown -g0 -y
    5. Reboot each node in the cluster.

      • SPARC:

        ok boot
      • x86:

                              <<< Current Boot Parameters >>>
        Boot path: /pci@0,0/pci8086,2545@3/pci8086,1460@1d/pci8086,341a@
        Boot args:
        Type b [file-name] [boot-flags] <ENTER> to boot with options
        or   i <ENTER>                          to enter boot interpreter
        or   <ENTER>                            to boot with defaults
                          <<< timeout in 5 seconds >>>
        Select (b)oot or (i)nterpreter: b
  2. 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.

  3. From one node of the cluster, run the scgdevs(1M) command.

  4. On each node, verify that the scgdevs command has completed 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