"John R. Jackson" wrote:
>
> >/usr/local/bin/tar -cvf - /home | rsh linux-host dd of=/dev/nst0
> >
> >(you may want to specify '-b blocksize' to the tar command... and
> > 'bs=blocksize' to the dd)
>
> The only problem with using dd like this is that dd does not do output
> reblocking. It takes whatever record size comes in (i.e. the size of
> the read()) and that's what it writes.
As far as I have used dd on Linux, I can recommend "obs=32k". It does
the trick of reblocking.
Once I had a slow network between a DLT drive and the host I wanted to
backup from:
ssh hostname "/sbin/dump 0af - /" | dd obs=32k of=$TAPE
...was a pain for the tape drive
My first guess using a buffer with dd
ssh host "/sbin/dump 0af - /" | dd bs=100M | dd obs=32k of=$TAPE
didn't succeed, but when I used
ssh host "/sbin/dump 0af - /" | dd obs=100M | dd obs=32k of=$TAPE
the tape drive rocked!
Even if the manpage tells you: "if you specify bs, ibs and obs will be
set to bs", dd will do no reblocking in this case.
