System Administration Guide
Chapter 8, Administering virtual disks

Allocating or modifying disk pieces

Allocating or modifying disk pieces

You can allocate disk pieces either while creating a new virtual disk, or by selecting an existing virtual disk (of a type that supports more than one piece) and choosing New from the Piece menu in the Virtual Disk Manager.

You can specify these parameters:

The disk map shows which parts of the device have already been assigned to a virtual disk and which are free. It shows the virtual disk pieces allocated on the device, and the disk divisions allocated on the device. (Note that space allocated to divvy divisions can only be assigned to a simple virtual disk.)

NOTE: You cannot allocate the free section of the root disk (/dev/dsk/0s1) shown on the disk map; this is used by the root filesystem. You cannot allocate free space that has been given over to divisions, created using divvy(ADM), as the division mechanism is incompatible with virtual disks; see ``Converting filesystems to virtual disks''.

You can select a free section in the disk map; the offset and length fields will be updated appropriately. (You can also manually reduce the length field from the maximum size available, which is selected by default.)

If you are creating a simple virtual disk, you can overlay a single division with a single disk piece, in order to convert the division into a virtual disk. (Once a division is overlaid by a simple virtual disk, the division is deleted.)

For RAID 0, 1, 4 and 5 arrays, each piece must be of identical size. The first time you create a piece for such a disk, the piece length is fixed; all subsequent pieces you add to the array are forced to that size.

The Virtual Disk Manager software does not allow disk pieces to be added to an existing RAID 10 or RAID 53 configuration. If you need to add another piece, create the extra mirror or array piece with the Virtual Disk Manager, then exit and edit /etc/dktab manually to add the extra piece. The format of this file is described in dktab(F). You will need to move the definition of the new virtual disk piece so that it occurs before the definition of the virtual disk that uses it.

If the virtual disk has a cluster size defined, then the disk length (size) must be a multiple of the cluster size. If this is not the case then the length is decreased appropriately and you are prompted to confirm this new size.

All pieces must be allocated before the virtual disk can be created.

NOTE: When you add a new piece to an array that has out-of-date parity or is out-of-service, a parity restore will be started automatically after the reconfiguration has completed. This is not shown by the progress slider bar. The list of virtual disks is refreshed when the progress slider bar reaches 100% and the reconfigured virtual disk will be marked as having bad parity. When the restore has completed and the display refresh interval has elapsed, the reconfigured virtual disk will be shown with up-to-date parity (or no pieces out-of-service).