On Wed, Jun 11 2008, Alan D. Brunelle wrote: > Jens Axboe wrote: > > On Wed, Jun 11 2008, Alan D. Brunelle wrote: > >> Dmitri Monakhov wrote: > >> > >> Could it be that in the first case you will have merges, thus creating > >> fewer/larger I/O requests? Running iostat -x during the two runs, and > >> watching the output is a good first place to start. > > > > I think it's mostly down to whether a specific drive is good at doing > > 124kb writes + 4k seek (and repeat) compared to regular streaming > > writes. The tested disk was SATA with write back caching, there should > > be no real command overhead gain in those size ranges. > > > > Probably true, I'd think the iostat -x data would be very helpful though. Definitely, the more data the better :). I already asked for blktrace data, that should give us everything we need. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
