Using dd to Make a Clone of a Drive
Giorgos Keramidas
keramida at ceid.upatras.gr
Thu Feb 9 14:02:45 PST 2006
On 2006-02-09 14:36, Martin McCormick <martin at dc.cis.okstate.edu> wrote:
> After installing FreeBSD5.4, the ISC dhcp server and ISC bind
> on a hard drive, I wanted to clone that drive to a second drive so as
> to generate a second server, using what I had already installed as a
> template. I used the following command:
>
> dd if=/dev/da0 of=/dev/da1 bs=512
>
> It turns out that dd defaults to 512-byte blocks so I didn't
> really need the bs=512, but I am not sure I haven't made some other
> type of mistake. The dd command has been running for about 4 hours on
> a very fast system, with a 1-gig processor, 1 gig of RAM and two 31-GB
> drives. One would think it should have finished by now, but it is
> still running. Is this a valid method of copying the entire contents
> of one drive to another? Thank you.
Bah! That's too slow for my taste. I would usually go for a newfs,
dump, and restore option. For instance, to create a copy of /usr on a
second disk:
newfs -U /dev/ad1s1a
mount /dev/ad1s1a /mnt
dump -0 -a -L /usr | ( cd /mnt ; restore ruvf - )
Copying with dd(1) is not as fast :)
More information about the freebsd-questions
mailing list