Re: [Dump-users] performance difference??

[Ken G. <ke...@pe...>]

>>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 machine?
> 
> 	* try getting dump out of the equation, and reproduce the timings with
> something simple like a dd.
> 
> 	* try dumping to /dev/null and see the speed difference (get 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....

Thanks,
Ken