Re: Using dd to copy a disk.

[Bret Comstock Waldow <bwaldow@alum.mit.edu>]

On Mon, 2003-07-28 at 15:53, Bill Moseley wrote:
>  I need to clone a disk.  The source is a 3ware hardware RAID 1 array.  
> >From Linux it looks like /dev/sda

<snip>

> Can I build a new bare metal drive on /dev/hda using dd
> 
>    dd if=/dev/sda of=/dev/hda

I don't know, but I have (possibly useless) comments.

I use dd to copy entire drives and partitions (it's my backup scheme). 
Since it works at both the /dev/hda and /dev/hdaX levels, I think it
might.

If there's a lot of angst about trying it, you might do this experiment:

dd if=/dev/hda of=/dev/null bs=512

It won't prove the whole thing will work, but if it emits errors, it
might prove it won't before you go on to try it.

I do it this way:
date; dd if=/dev/hda of=/dev/null bs=512; date
'cause I'm interested in how long it takes...

If you've got the new single drive, you could just try it.  The worst
likely is you'd need to re-do the new drive.  I assume the new drive is
big enough?

I'd like to know the outcome if you'd post it to the group.

Cheers,
Bret
-- 
bwaldow at alum.mit.edu