Re: Where is the performance bottleneck?

[Jens Axboe <axboe@suse.de>]

On Wed, Aug 31 2005, Holger Kiehl wrote:
> ># ./oread /dev/sdX
> >
> >and it will read 128k chunks direct from that device. Run on the same
> >drives as above, reply with the vmstat info again.
> >
> Using kernel 2.6.12.5 again, here the results:

[snip]

Ok, reads as expected, like the buffered io but using less system time.
And you are still 1/3 off the target data rate, hmmm...

With the reads, how does the aggregate bandwidth look when you add
'clients'? Same as with writes, gradually decreasing per-device
throughput?

-- 
Jens Axboe

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