Date: Thu, 30 Aug 2007 10:04:41 -0600 From: "Kenneth D. Merry" <ken@kdm.org> To: Scott Long <scottl@samsco.org> Cc: FREEBSD - SCSI - LIST <freebsd-scsi@freebsd.org> Subject: Re: performance with LSI SAS 1064 Message-ID: <20070830160441.GA50706@nargothrond.kdm.org> In-Reply-To: <46D6D9C3.6050202@samsco.org> References: <46D5E17F.3070403@samsco.org> <71d0ebb0708291416v17351c65u7ccc1b7bbe0271d2@mail.gmail.com> <46D5E5B1.207@samsco.org> <71d0ebb0708291506i49649a60l8006deafb20891ac@mail.gmail.com> <46D63710.1020103@freebsd.org> <71d0ebb0708300502x632fe83bo617f84ca2008dc7d@mail.gmail.com> <46D6BEC0.1050104@samsco.org> <46D6CB71.4030707@freebsd.org> <71d0ebb0708300737o4fc7966dj61cf0e68482da398@mail.gmail.com> <46D6D9C3.6050202@samsco.org>
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The "tagged openings now ..." message was hidden under bootverbose by Jordan 8 years ago. :) So it won't show up on the console, unless you boot with -v. Ken On Thu, Aug 30, 2007 at 08:52:51 -0600, Scott Long wrote: > 54MB/s is reasonable for 10k 2.5" disks. You might be able to squeeze > some more performance by upgrading to FreeBSD 7.0. I _do_not_ recommend > playing with the queue depth controls unless your console logs are > getting quickly filled with messages about it. > > Scott > > > Lutieri G. wrote: > >This is my disks: > > > >Seagate Savvio(ST913401ss) 10K.1 SAS 3Gb/s 73-GB Hard Drive. In the > >manual file i found this information: > > > >Queue tagging (up to 64 queue tags supported) > > > >Is this the max # for setting using camcontrol?! syntax like this: > >camcontrol tags da0 -N 64 ?? > > > >2007/8/30, Eric Anderson <anderson@freebsd.org>: > >>Scott Long wrote: > >>>Lutieri G. wrote: > >>>>2007/8/30, Eric Anderson <anderson@freebsd.org>: > >>>>>I'm confused - you said in your first post you were getting 3MB/s, > >>>>>where > >>>>> above you show something like 55MB/s. > >>>>Sorry! using blogbench i got 3MB/s and 100% busy. Once is 100% busy i > >>>>thinked that 3MB/s is the maximum speed. But i was wrong... > >>>%busy is a completely useless number for a anything but untagged, > >>>uncached disk subsystems. It's only an indirect measure of latency, and > >>>there are better tools for measuring latency (gstat). > >>> > >>>>>You didn't say what kind of disks, or how many, the configuration, etc > >>>>>- > >>>>>so it's hard to answer much. The 55MB/s seems pretty decent for many > >>>>>hard drives in a sequential use state (which is what dd tests really). > >>>>> > >>>>SAS disks. Seagate, i don't know what is the right model of disks. > >>>> > >>>>Ok. If 55Mb/s is a decent speed i'm happy. I'm getting problems with > >>>>squid cache and maybe should be a problem related with disks. But... > >>>>i'm investigating and discharging problems. > >>>> > >>>> > >>>>>Your errors before were probably caused because your queue depth is set > >>>>>to 255 (or 256?) and the adapter can't do that many. You should use > >>>>>camcontrol to reduce it, to maybe 32. See the camcontrol man page for > >>>>>the right usage. It's something that needs setting on every boot, so a > >>>>>startup file is a good place for it maybe. > >>>>> > >>>>Is there any way of get the right number to reduce?! > >>>> > >>>If you're seeing erratic performance in production _AND_ you're seeing > >>>lots of accompanying messages on the console about tag depth jumping > >>>around, you can use camcontrol to force the depth to a lower number of > >>>you're choosing. This kind of problem is pretty rare, though. > >>Scott, you are far more of a SCSI guru than I, so please correct me if > >>this is incorrect. Can't you get a good estimate, by knowing the queue > >>depth of the target(s), and dividing it by the number of initiators? So > >>in his case, he has one initiator, and (let's say) one target. If the > >>queue depth of the target (being the Seagate SAS drive) is 128 (see > >>Seagate's paper here: > >>http://www.seagate.com/staticfiles/support/disc/manuals/enterprise/savvio/Savvio%2015K.1/SAS/100407739b.pdf > >>), then he should have to reduce it down from 25[56] to 128, correct? > >> > >>With QLogic cards connected to a fabric, I saw queue depth issues under > >>heavy load. > >> > >>Eric > >> > >> > >> > >> > >> > > > > > > _______________________________________________ > freebsd-scsi@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-scsi > To unsubscribe, send any mail to "freebsd-scsi-unsubscribe@freebsd.org" -- Kenneth Merry ken@kdm.org
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