2008/9/25 Joshua Baker-LePain <jlb17 AT duke DOT edu>:
> On Thu, 25 Sep 2008 at 4:42pm, Jamie Penman-Smithson wrote
>
>> The holding disk is on a local [lowly] IDE drive. The data being
>> backed up is on the whole comprised relatively large (couple of gig)
>> files stored on SAN over fibre. At first I thought that the adverse
>
> Have you benchmarked the SAN from this host independent of amanda?  Try
> something like bonnie++ or even just 'tar cO /foo | cat > /dev/null'.

$ time sudo tar cO /foo | cat > /dev/null

real    12m59.903s
user    0m24.795s
sys     2m48.930s

>> performance was due to the IDE disk, however after disabling the
>> holding disk it actually takes 4 hours longer to complete. I've
>
> If you can't read from the SAN fast enough to keep the tape streaming, then
> it *would* take even longer without a holding disk.

What I can't understand is how using tar -cvf /dev/st0 /foo (without
using mbuffer for example) takes around 3-4 hours to fill a 200 GB
tape..

<snip>
>> The tape drive is part of an IBM TotalStorage 3582 tape library.
>
> LTO1?

Yes.

Thanks,

-- 
-Jamie L. Penman-Smithson <jpenman.smithson AT gmail DOT com>