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Taking a disk inventory

How to select disks

Decide which disks you want to place under VxVM control. The other disks in your configuration are not affected. Disks may be brought under VxVM control in two ways:

• Encapsulated disks—Data in all existing file systems and partitions on the disk are preserved.
• Initialized disks—Data on the disks is removed.

Verifying disk contents

Verify the disk contents. Answer the following questions and list the data for your convenience.

1. Make sure you are aware of the contents of each disk. Determine which disks can be encapsulated (data is preserved) or initialized (data is removed).
2. Do you want to place the system root disk under VxVM control?
   
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3. Do you want to either encapsulate or initialize all disks on a controller together? Identify the controllers (for example c0t0d0).
   
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4. Identify the disks to be encapsulated, initialized, or excluded, in a table similar to the following.

    

   Disk ID	Encapsulate, Initialize, Exclude

5. Verify that the disks that are to be encapsulated by VxVM have two free partitions and a recommended amount of 32MB of free space.

   The free space must be at the beginning or end of the disk and must not belong to a partition. This space is used for storing disk group configurations and a disk label that ensures VxVM can identify the disk, even if it is moved to a different address or controller. It is also used to keep track of disk configuration and to ensure correct recovery.

   The boot disk is a special case. If no other space is available, VxVM attempts to allocate space usually reserved for swap by shrinking the swap partition. This process is known as swap relocation and, if necessary, happens automatically during root disk encapsulation.

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     Note   Although it is possible to put disks with no free space under VxVM control, this is only used as a migration strategy. Many VxVM capabilities based on disk identity are available only for disks with the required free space. See the vxdisk(1M) manual page for information on the nopriv disk type.

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6. If you are encapsulating the boot (root) disk:
   1. Before encapsulating your boot disk, set the EEPROM variable use-nvramrc? to true. This will enable VxVM to take advantage of boot disk aliases to identify the mirror of the boot disk if a replacement is needed. If this variable is set to false, you must determine which disks are bootable yourself. Set this variable to true as follows:

      # eeprom "use-nvramrc?=true"

      If your root disk is connected over fabric, you should check the Hardware Compatibility List at http://support.veritas.com to see if your device type is supported for boot encapsulation

   2. Use the prtvtoc(1M) command to record the layout of the partitions on the unencapsulated boot disk (/dev/rdsk/c0t0d0s2 in this example):

      # prtvtoc /dev/rdsk/c0t0d0s2

      Record the output from this command for future reference.

   3. To encapsulate the boot disk, tag the swap partition as swap so that it is possible to dump to that partition later. See format(1M) for information on tagging the swap partition.

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        Note   If the path to an aliased boot device is different from the path in the /devices directory, aliases may not function correctly. This might happen if the pathname is incorrectly entered at the command line, or if the device's pathname changes at a later date.

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