Dynamic Root Disk A.3.12.* Administrator's Guide

In Example 2-1, the disk with the active system image is /dev/dsk/c2t3d0. You need to choose
a free disk to be the target of the drd clone command. Your system may have many more disks
than Example 2-1 shows.
The target disk must:
• Be a block device special file.
• Be writeable by the system.
• Not currently be in use by other applications.
• Be large enough to hold a copy of each logical volume in the root group.
The target's physical disk need not be as large as the disk allocated for the root group, as long
as there is enough space for a copy of each logical volume in the root group. However, the disk
needs to be larger than the used space in each logical volume because each logical volume will
be created with the number of physical extents currently allocated to the corresponding root group
logical volume.
Example 2-1 shows three system disks: /dev/dsk/c0t0d0, /dev/dsk/c1t2d0, and /dev/
dsk/c2t3d0. You need to determine which disks are available and large enough.
Using other utilities to determine disk availability
You can determine which disks are in use with the lvm(7M) (Logical Volume Manager) and VxVM
(Veritas Volume Manager) commands. For example, to see which disks are in use by lvm, enter
this command:
# /usr/sbin/vgdisplay -v | /usr/bin/more
and look in the output for PV Name, which describes physical volumes.
This information is under the Physical Volumes heading. It looks similar to this:
--- Physical Volumes ---
PV Name /dev/dsk/c2t3d0
PV Status available
Total PE 4340
Free PE 428
Autoswitch On
You can use the vxdisk -o alldgs list command to display information about all disks
managed by VxVM. Do not specify any disk in use by VxVM as a clone target.
The swapinfo command can be used to display information about disks currently used for swap.
The HP System Management Homepage, hpsmh(1M), or System Administration Manager, sam(1M),
can be used to investigate the disks on the system and their current usage.
Using DRD for limited disk availability checks
You can use drd clone with the -p option to get minimal availability information about a disk.
(See the following section for an example.)
The drd clone command performs the following checks:
• If the disk is currently in use by the LVM Manager, it is rejected by the drd clone operation.
• If the disk is currently in use by the VxVM Manager, it will be accepted only if the following
two conditions are met:
◦ The disk is an inactive image managed by DRD
◦ The extended option -x overwrite=true is specified on the drd clone command
• If the disk is not currently in use by LVM or VxVM, but contains LVM, VxVM, or boot records,
it is only accepted as a drd clone target if -x overwrite=true is specified on the drd
clone command.
Using other utilities to determine disk availability 11