Sun Cluster Software Installation Guide for Solaris OS

SPARC: Creating Disk Groups in a Cluster

This section describes how to create VxVM disk groups in a cluster.

The following table lists the tasks to perform to create VxVM disk groups for Sun Cluster configurations.

Table 4–2 SPARC: Task Map: Creating VxVM Disk Groups

Task 

Instructions 

1. Create disk groups and volumes. 

SPARC: How to Create and Register a Disk Group

2. If necessary, resolve any minor-number conflicts between disk device groups by assigning a new minor number. 

SPARC: How to Assign a New Minor Number to a Disk Device Group

3. Verify the disk groups and volumes. 

SPARC: How to Verify the Disk Group Configuration

ProcedureSPARC: How to Create and Register a Disk Group

Use this procedure to create your VxVM disk groups and volumes.


Note –

After a disk group is registered with the cluster as a disk device group, you should never import or deport a VxVM disk group by using VxVM commands. The Sun Cluster software can handle all cases where disk groups need to be imported or deported. See Administering Disk Device Groups in Sun Cluster System Administration Guide for Solaris OS for procedures about how to manage Sun Cluster disk device groups.


Perform this procedure from a node that is physically connected to the disks that make the disk group that you add.

Before You Begin

Perform the following tasks:

Steps
  1. Become superuser on the node that will own the disk group.

  2. Create a VxVM disk group and volume.

    If you are installing Oracle Real Application Clusters, create shared VxVM disk groups by using the cluster feature of VxVM as described in the VERITAS Volume Manager Administrator's Reference Guide. Otherwise, create VxVM disk groups by using the standard procedures that are documented in the VxVM documentation.


    Note –

    You can use Dirty Region Logging (DRL) to decrease volume recovery time if a node failure occurs. However, DRL might decrease I/O throughput.


  3. If the VxVM cluster feature is not enabled, register the disk group as a Sun Cluster disk device group.

    If the VxVM cluster feature is enabled, do not register a shared disk group as a Sun Cluster disk device group. Instead, go to SPARC: How to Verify the Disk Group Configuration.

    1. Start the scsetup(1M) utility.


      # scsetup
      
    2. Choose the menu item, Device groups and volumes.

    3. Choose the menu item, Register a VxVM disk group.

    4. Follow the instructions to specify the VxVM disk group that you want to register as a Sun Cluster disk device group.

    5. When finished, quit the scsetup utility.

    6. Verify that the disk device group is registered.

      Look for the disk device information for the new disk that is displayed by the following command.


      # scstat -D
      
Next Steps

Go to SPARC: How to Verify the Disk Group Configuration.

Troubleshooting

Failure to register the device group – If when you attempt to register the disk device group you encounter the error message scconf: Failed to add device group - in use, reminor the disk device group. Use the procedure SPARC: How to Assign a New Minor Number to a Disk Device Group. This procedure enables you to assign a new minor number that does not conflict with a minor number that is used by existing disk device groups.

Stack overflow – If a stack overflows when the disk device group is brought online, the default value of the thread stack size might be insufficient. On each node, add the entry set cl_comm:rm_thread_stacksize=0xsize to the /etc/system file, where size is a number greater than 8000, which is the default setting.

Configuration changes – If you change any configuration information for a VxVM disk group or volume, you must register the configuration changes by using the scsetup utility. Configuration changes you must register include adding or removing volumes and changing the group, owner, or permissions of existing volumes. See Administering Disk Device Groups in Sun Cluster System Administration Guide for Solaris OS for procedures to register configuration changes to a disk device group.

ProcedureSPARC: How to Assign a New Minor Number to a Disk Device Group

If disk device group registration fails because of a minor-number conflict with another disk group, you must assign the new disk group a new, unused minor number. Perform this procedure to reminor a disk group.

Steps
  1. Become superuser on a node of the cluster.

  2. Determine the minor numbers in use.


    # ls -l /global/.devices/node@1/dev/vx/dsk/*
    
  3. Choose any other multiple of 1000 that is not in use to become the base minor number for the new disk group.

  4. Assign the new base minor number to the disk group.


    # vxdg reminor diskgroup base-minor-number
    

Example 4–2 SPARC: How to Assign a New Minor Number to a Disk Device Group

This example uses the minor numbers 16000-16002 and 4000-4001. The vxdg reminor command reminors the new disk device group to use the base minor number 5000.


# ls -l /global/.devices/node@1/dev/vx/dsk/*
/global/.devices/node@1/dev/vx/dsk/dg1
brw-------   1 root     root      56,16000 Oct  7 11:32 dg1v1
brw-------   1 root     root      56,16001 Oct  7 11:32 dg1v2
brw-------   1 root     root      56,16002 Oct  7 11:32 dg1v3
 
/global/.devices/node@1/dev/vx/dsk/dg2
brw-------   1 root     root      56,4000 Oct  7 11:32 dg2v1
brw-------   1 root     root      56,4001 Oct  7 11:32 dg2v2
# vxdg reminor dg3 5000

Next Steps

Register the disk group as a Sun Cluster disk device group. Go to SPARC: How to Create and Register a Disk Group.

ProcedureSPARC: How to Verify the Disk Group Configuration

Perform this procedure on each node of the cluster.

Steps
  1. Verify that only the local disks are included in the root disk group, and disk groups are imported on the current primary node only.


    # vxdisk list
    
  2. Verify that all volumes have been started.


    # vxprint
    
  3. Verify that all disk groups have been registered as Sun Cluster disk device groups and are online.


    # scstat -D
    
Next Steps

Go to Configuring the Cluster.