Date: Thu, 11 Jan 2007 16:07:22 -0500 From: "Ahnjoan Amous" <ahnjoan@gmail.com> To: "Scott Long" <scottl@samsco.org> Cc: freebsd-fs@freebsd.org Subject: Re: aac scsi raid driver performance Message-ID: <5e575c8a0701111307s5a839b82ra4ba5c45d554d3b9@mail.gmail.com> In-Reply-To: <45A6A138.8090208@samsco.org> References: <5e575c8a0701111155l859d0ecif617dbda43cef842@mail.gmail.com> <45A6A138.8090208@samsco.org>
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I reset the controller to the defaults for everything before I did the installation. Each of the containers were created with the following options. Container Type - RAID 0 Container Label - data03 Container Size - 279.396 GB Chunk Size - 64KB Read Caching (Yes/No) - Y Write Caching : Enable when protected Create RAID 5 via - N/A Then the controller itself has a single cache option Drives Write Cache - Disabled Thanks Ahnjoan On 1/11/07, Scott Long <scottl@samsco.org> wrote: > Did you enable read caching for the arrays? > > Scott > > > Ahnjoan Amous wrote: > > I'm trying to find possible explanations for slow concurrent writes > > through the > > aac driver. This machine runs under 1% load and has less than 4 > > transfers per > > second to the drives in question when not being used for testing. > > > > When I attempt sequential "dd"s as follow, the results are better then > > 70MB/sec. > > dd if=/dev/zero of=/data02/helloworld bs=1m count=1000 > > 1048576000 bytes transferred in 13.886718 secs (75509274 bytes/sec) > > dd if=/dev/zero of=/data03/helloworld bs=1m count=1000 > > 1048576000 bytes transferred in 14.011323 secs (74837758 bytes/sec) > > > > When I attempt concurrent "dd"s as follow, with a 1 second sleep interval > > between starts, the results are better than 40MB/sec > > dd if=/dev/zero of=/data02/helloworld bs=1m count=1000 & > > sleep 1 > > dd if=/dev/zero of=/data03/helloworld bs=1m count=1000 & > > 1048576000 bytes transferred in 25.269555 secs (41495626 bytes/sec) > > 1048576000 bytes transferred in 24.935765 secs (42051086 bytes/sec) > > > > When I attempt concurrent "dd"s as follow, the results are little better > > than > > 20MB/sec > > dd if=/dev/zero of=/data02/helloworld bs=1m count=1000 & > > dd if=/dev/zero of=/data03/helloworld bs=1m count=1000 & > > 1048576000 bytes transferred in 44.963408 secs (23320652 bytes/sec) > > 1048576000 bytes transferred in 45.010065 secs (23296478 bytes/sec) > > > > I can't account for what causes the huge difference however the results are > > reproducible. I've run the tests dozens and dozens of times now, first > > blaming > > the em driver for my slow ggatec/ggated results, then GEOM for my slow > > local > > mirroring after eliminating the network, and finally blaming the aac driver > > after removing GEOM from the equation. If anyone has ideas on what I might > > look at or change or test I would love to hear. > > > > > > ****** Misc. Information ****** > > root:somehost:~ > df -k > > Filesystem 1K-blocks Used Avail Capacity Mounted on > > /dev/aacd2s1e 2026030 1024532 839416 55% /data02 > > /dev/aacd3s1e 2026030 1024532 839416 55% /data03 > > Hardware - > > aac - Dell PERC3/Di U160 > > aacd2 - hardware RAID 0, w/1 U320 300G drive > > aacd3 - hardware RAID 0, w/1 U320 300G drive > > _______________________________________________ > > freebsd-fs@freebsd.org mailing list > > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" > >
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