Administering virtual disks

Adding virtual disks

To add a virtual disk, you create a virtual disk, allocate pieces of physical disks to the virtual disk, then mount the virtual disk.

To create a virtual disk, run the Virtual Disk Manager, and select New from the Disk menu. Accept the default values provided for the Vdisk type and Device entries or change the selections to suit your system requirements. Once you have created a virtual disk filesystem, you may mount it using the Filesystem Manager, as described in ``Mounting and unmounting filesystems''.

NOTE: Because virtual disks are intended for systems with more than one hard disk, your secondary disks must be configured as described in ``Adding secondary hard disks''. When configuring these secondary disks with mkdev(ADM), do not run divvy(ADM); the Virtual Disk Manager does not use the disk divisions created by this utility except when migrating existing divisions to virtual disks.

To add a virtual disk:

Allocate one or more disk pieces for the virtual disk:
- Select a disk piece and click on Allocate piece. Select a device (physical disk) for the piece. Using the disk map (showing the virtual disk layout), select a free area of the disk and assign it to the piece.
  Disk pieces are located by their offset (in blocks, from block 0 of the partition) and their size. So, to create a 1000-block disk piece you might select the first free section of /dev/dsk/1s1 (the first partition on the second physical hard disk) and enter the value ``1000'' into the ``Length'' field.
- Click on OK to confirm your piece definition.
Continue allocating pieces until all the pieces in the virtual disk are defined.
Click on Create to create the virtual disk. If the virtual disk type uses parity data (RAID 1, 4, and 5) you will be prompted whether you want to restore parity at this time. You are prompted for the type of filesystem to place on the virtual disk. You have the option of creating a filesystem at this time, or later; see ``Creating filesystems on virtual disks'' for details.

The Virtual Disk Manager permits you to create any configuration of virtual disk, and to allocate pieces to the disks as you like. Not all possible virtual disks make sense. For example, you can create a striped disk and specify that all the pieces reside on one physical hard disk; this will, however, lead to extremely poor performance (as the virtual disk will be unable to read or write data in parallel across the stripe).