Encapsulating a disk


Encapsulating a disk requires that the system be rebooted several times. Schedule performance of this procedure for a time when this does not inconvenience users.

This section describes how to encapsulate a disk for use in VxVM. Encapsulation preserves any existing data on the disk when the disk is placed under VxVM control.

To prevent the encapsulation from failing, make sure that the following conditions apply:

Only encapsulate a root disk if you also intend to mirror it. There is no benefit in root-disk encapsulation for its own sake.

Use the format or fdisk commands to obtain a printout of the root disk partition table before you encapsulate a root disk. For more information, see the appropriate manual pages. You may need this information should you subsequently need to recreate the original root disk.

You cannot grow or shrink any volume (rootvol, usrvol, varvol, optvol, swapvol, and so on) that is associated with an encapsulated root disk. This is because these volumes map to physical partitions on the disk, and these partitions must be contiguous.

When the boot disk is encapsulated or mirrored, a device path alias is added to the NVRAMRC in the SPARC EEPROM. These device aliases can be used to set the system's boot device.

For more information, see the devalias and boot-device settings in the SUN documentation.


If the root disk is encapsulated and the dump device is covered by the swap volume, it is not safe to use the savecore -L operation because this overwrites the swap area. Configure a dedicated dump device on a partition other than the swap area.

To encapsulate a disk for use in VxVM

  1. Select Encapsulate one or more disks from the vxdiskadm main menu.

    Your system may use device names that differ from the examples shown here.

    At the following prompt, enter the disk device name for the disks to be encapsulated:

    Select disk devices to encapsulate: 
    [<pattern-list>,all,list,q,?] device name

    The pattern-list can be a single disk, or a series of disks and/or controllers (with optional targets). If pattern-list consists of multiple items, those items must be separated by white space.

    If you do not know the address (device name) of the disk to be encapsulated, enter l or list at the prompt for a complete listing of available disks.

  2. To continue the operation, enter y (or press Return) at the following prompt:
    Here is the disk selected. Output format: [Device]
    device name
    Continue operation? [y,n,q,?] (default: y) y
  3. Select the disk group to which the disk is to be added at the following prompt:
    You can choose to add this disk to an existing disk group or to 
    a new disk group. To create a new disk group, select a disk 
    group name that does not yet exist.
    Which disk group [<group>,list,q,?]
  4. At the following prompt, either press Return to accept the default disk name or enter a disk name:
    Use a default disk name for the disk? [y,n,q,?] (default: y)
  5. To continue with the operation, enter y (or press Return) at the following prompt:
    The selected disks will be encapsulated and added to the 
    disk group name disk group with default disk names.
    device name
    Continue with operation? [y,n,q,?] (default: y) y
  6. To confirm that encapsulation should proceed, enter y (or press Return) at the following prompt:
    The following disk has been selected for encapsulation.
     Output format: [Device]
    device name
    Continue with encapsulation? [y,n,q,?] (default: y) y

    A message similar to the following confirms that the disk is being encapsulated for use in VxVM and tells you that a reboot is needed:

    The disk device device name will be encapsulated and added to
    the disk group diskgroup with the disk name diskgroup01.
  7. For non-root disks, you can now choose whether the disk is to be formatted as a CDS disk that is portable between different operating systems, or as a non-portable sliced disk:
    Enter the desired format [cdsdisk,sliced,q,?]
    (default: cdsdisk)

    Enter the format that is appropriate for your needs. In most cases, this is the default format, cdsdisk. Note that only the sliced format is suitable for use with root, boot or swap disks.

  8. At the following prompt, vxdiskadm asks if you want to use the default private region size of 65536 blocks (32MB). Press Return to confirm that you want to use the default value, or enter a different value. (The maximum value that you can specify is 524288 blocks.)
    Enter desired private region length [<privlen>,q,?]
    (default: 65536)
  9. If you entered cdsdisk as the format in step 7, you are prompted for the action to be taken if the disk cannot be converted this format:
    Do you want to use sliced as the format should cdsdisk
    fail? [y,n,q,?] (default: y)

    If you enter y, and it is not possible to encapsulate the disk as a CDS disk, it is encapsulated as a sliced disk. Otherwise, the encapsulation fails.

  10. vxdiskadm then proceeds to encapsulate the disks. You should now reboot your system at the earliest possible opportunity, for example by running this command:
    # shutdown -g0 -y -i6

    The /etc/vfstab file is updated to include the volume devices that are used to mount any encapsulated file systems. You may need to update any other references in backup scripts, databases, or manually created swap devices. The original /etc/vfstab file is saved as /etc/vfstab.prevm.

  11. At the following prompt, indicate whether you want to encapsulate more disks (y) or return to the vxdiskadm main menu (n):
    Encapsulate other disks? [y,n,q,?] (default: n) n

    The default layout that is used to encapsulate disks can be changed.

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