[RndTbl] disk cloning

[Trevor Cordes]

On 2009-07-23 Dan Martin wrote:
> 
> On my Mac, I am switching to an alternate boot drive so that I can  
> copy my usual boot drive to a third drive using the dd command from  
> the Terminal.  However, I am encountering an IO error, and there are  
> differences between the original and the copy as shown using
> FileMerge.

You can get by IO errors with conv=noerror, which I use for all my dd
clones:

dd if=/dev/sda of=wherever conv=noerror bs=1M

Also handy with sysresccd.org boot (and other live cds) is you can
start the nic and dd over the network:

dd if=/dev/sda conv=noerror | ssh root at yourfs 'cat > /tmp/image.dd'

or, why not store the img compressed:

dd if=/dev/sda conv=noerror | gzip -c9 | ssh root at yourfs 'cat
> /tmp/image.dd.gz'

Of course, this all works better when your source CPU is fast and
network is fast.  You could move the gzip to the server if it has a
faster cpu... or bzip... or...