increasing dd disk to disk transfer rate

[John-Mark Gurney]

Ivan Voras wrote this message on Thu, Jan 12, 2006 at 18:48 +0100:
> Bakul Shah wrote:
> >>In the last episode (Jan 12), Christoph Kukulies said:
> 
> >>dd if=/dev/ad2 conv=noerror,sync bs=64k | dd of=/dev/ad3 bs=64k
> >
> >
> >So now on the new disk he has files with random blocks of
> >zeroes and *no* error indication of which files are so
> >trashed.  This is asking for trouble.  Silent erros are
> >worse.
> >
> >He ought to do a file level copy, not disk level copy on
> >unix.  That way he knows *which* files are trashed and can do
> 
> The problem is, FreeBSD panics when it encounters bad sectors in 
> filesystem metadata. I had the same situation ~a month ago and gave up, 
> restoring from old backups. It will also probably panic on corrupted or 
> zeroed metadata, but at least it's on a readable disk...

Recovery can be possible with ffsrecov.py:
http://people.freebsd.org/~jmg/ffsrecov/

-- 
  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."