Date: Sat, 13 Jan 2007 10:03:20 -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: <5e575c8a0701130703y6c528cecoed9019472a4956c8@mail.gmail.com> In-Reply-To: <45A7551C.5030006@samsco.org> References: <5e575c8a0701111155l859d0ecif617dbda43cef842@mail.gmail.com> <45A6A138.8090208@samsco.org> <5e575c8a0701111307s5a839b82ra4ba5c45d554d3b9@mail.gmail.com> <45A7551C.5030006@samsco.org>
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Scott - I disabled read cache on both containers and the end result for my write tests is still 25M/sec. I have included the output to aaccli to confirm that I disabled the correct cache. Maybe I'm just expecting too much from the PE2650 with PERC 3/di. I know there are a lot of variables in this equation but what speeds would you expect for this U160 scsi raid controller front ending U320 devices on a box with no load and no i/o, other than two concurrent dd's to two different ufs mounted hardware raid 0 volumes? Thanks Ahnjoan AAC0> container show cache 2 Read Cache Setting : DISABLE Write Cache Setting : ENABLE WHEN PROTECTED Write Cache Status : Active, protected AAC0> container show cache 3 Read Cache Setting : DISABLE Write Cache Setting : ENABLE WHEN PROTECTED Write Cache Status : Active, protected On 1/12/07, Scott Long <scottl@samsco.org> wrote: > Turn off read caching > > Ahnjoan Amous wrote: > > 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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