Re: [Dump-users] performance difference??

[Stelian P. <st...@po...>]

Le 20 sept. 05 =E0 17:54, Ken Godee a =E9crit :

>>> The machine I thought would have been faster,
>>> is less than half the speed???
>>>
>>> What should I be looking at to see if I can speed up the slower =20
>>> machine?
>>>
>>     * try getting dump out of the equation, and reproduce the =20
>> timings with
>> something simple like a dd.
>>     * try dumping to /dev/null and see the speed difference (get =20
>> the tape
>> drive out of equation)
>>
> Thanks for the reply.
>
> Working as best as possible using raw devices/150mb files, etc.
>
> As expected the faster(theoretically) machine produced
> higher speeds/transfers in both timed dd trials and dump -> /dev/null
> trails.
>
> The dump to /dev/null transfer rates where more than double that
> of the slower machine.
>
> So I guess this is not a dump issue, dump appears to be doing its
> job. I'll look towards drivers/tape drive (firmware?) etc.
>
> Next I'll just swap tape drives and see if transfer rates change any.
>
> Since it's not a dump issue, I'll just keep poking at it.
> Just drives me nuts that the actual transfer rate on the
> faster machine is half of the slower machine when doing
> backups. Aaarrrgg....

Good luck and keep us informed if you find anything. Your experience =20
can be useful to others on this list.

This is not the first time performance issues are reported here...

Stelian.