Date: Thu, 22 Mar 2007 15:43:47 +0200 From: Cheffo <cheffo@FreeBSD-BG.org> To: "roma.a.g" <roma.a.g@gmail.com> Cc: freebsd-performance@FreeBSD.ORG Subject: Re: Slow on heavy I/O operations. Message-ID: <46028813.5030209@FreeBSD-BG.org> In-Reply-To: <1465093066.20070322162026@gmail.com> References: <1036039198.20070321153412@gmail.com> <200703211354.l2LDsKnV080911@lurza.secnetix.de> <1465093066.20070322162026@gmail.com>
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Roman Gorohov. wrote: -CUT- > > That seems like true, and I forget to mention that 2/3 of swap is > located at physical disk(da0). > [idle@hst ~]#swapinfo > Device 1K-blocks Used Avail Capacity Type > /dev/da0s1b 524160 463300 60860 88% Interleaved > /dev/rvn0b 1048448 578724 469724 55% Interleaved > Total 1572608 1042024 530584 66% > > But what I can't understand - why such non-critical(as it seems to me) disk activity, > cause 100% busyness for disk? Its claim to be 40.000MB/s transfers, but > sometimes its 100% busy when iostat show only 1 MB/s. > > Regards, Roman. Imagine 1000 request per second and every request is 1KB, and compare it with a single request that is 1MB. In first variant your disk will be 100% busy and in the second 2-3%. I think you can guess why ? > > _______________________________________________ > freebsd-performance@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-performance > To unsubscribe, send any mail to "freebsd-performance-unsubscribe@freebsd.org" > > -- Best Wishes, Stefan Lambrev ICQ# 24134177
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