Re: Speed up xfsdump ?

[Bill Kendall <wkendall@xxxxxxx>]

Nicolas Kowalski wrote:
> On Tue, 13 Sep 2005, Tim Shimmin wrote:
>
>
> > On Mon, Sep 12, 2005 at 10:42:23AM -0700, Bryan J. Smith wrote:
> >
> > > Bill Kendall <wkendall@xxxxxxx> wrote:
> > >
> > > > Try the dump this way and see if performance improves:
> > > > xfsdump -J -f /dev/nst0 -b 1048576 -d 8192 /raid
> > > Agreed.  Play with the blocking/buffering options of xfsdump
> > > itself.
> > My 2 cents FWIW.
>
> [...]
>
> Using your tips, I also tested with this:
>
> xfsdump -J -f /dev/nst0 -S -p 300 -b 262144 /raid
>
> At the end, I have:
>
> xfsdump: dump size (non-dir files) : 28364432208 bytes
> xfsdump: dump complete: 4643 seconds elapsed
>
> This gives : 6109074 bytes/sec
>
> So the results are almost identical whatever blocksize or number of 
> dump files are specified to xfsdump... 
It might be helpful to determine if xfsdump is slow because of the
way it's interacting with the tape drive, or if it's just slow in
general on your filesystem. Try using "-f /dev/null" and see how
it performs. You don't need to specify -d/-S or -b in this case.

Bill