Thursday, April 26, 2007

Create a Clone Disk Drive

You can use the dd (data dump) command to create a backup disk drive. It will create a mirror image, which includes the partition table, of your boot disk by copying it bit by bit. In the example below, I'm using slice 2 because it represents the entire disk. Here's the syntax.

Disk to Disk (Ensure the disks are the same size)
#dd if=/dev/rdsk/c0t10d0s2 of=/dev/rdsk/c0t11d0s2 (default blocksize 512)

Blocksize is configurable (For RAIDs, we use larger blocksizes, e.g. 4k)
#dd if=/dev/rdsk/c0t10d0s2 of=/dev/rdsk/c0t11d0s2 bs=128

Disk to Tape
#dd if=/dev/rdsk/c0t10d0s2 of=/dev/rdsk/c0t11d0s2

Blocksize is configurable
#dd if=/dev/rdsk/c0t10d0s2 of=/dev/rmt/0 bs=128


Anonymous said...

Why are you shrinking the blocksize?

esofthub said...

anonymous, I did it for illustration purposes. I should have been clearer about that. For RAIDs, we normally use a larger block size and default for system disk. I appreciate your question.