Date: Wed, 29 Aug 2007 21:57:20 -0600 From: Scott Long <scottl@samsco.org> To: Eric Anderson <anderson@freebsd.org> Cc: FREEBSD - SCSI - LIST <freebsd-scsi@freebsd.org> Subject: Re: performance with LSI SAS 1064 Message-ID: <46D64020.3000503@samsco.org> In-Reply-To: <46D63710.1020103@freebsd.org> References: <71d0ebb0708291245g79d2141fx73cc8a6e76875944@mail.gmail.com> <46D5E17F.3070403@samsco.org> <71d0ebb0708291416v17351c65u7ccc1b7bbe0271d2@mail.gmail.com> <46D5E5B1.207@samsco.org> <71d0ebb0708291506i49649a60l8006deafb20891ac@mail.gmail.com> <46D63710.1020103@freebsd.org>
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Eric Anderson wrote: > Lutieri G. wrote: >> I've make a test with dd command: >> >> # time dd if=/dev/zero of=./8gbfile bs=1024k count=8192 >> 8192+0 records in >> 8192+0 records out >> 8589934592 bytes transferred in 155.653213 secs (55186362 bytes/sec) >> 0.007u 25.129s 2:35.69 16.1% 55+6039k 117+68628io 0pf+0w >> >> in other terminal i ran iostat while dd were running and I get this: >> >> # iostat -I 1 >> tty da0 pass0 cpu >> tin tout KB/t xfrs MB KB/t xfrs MB us ni sy in id >> 1 61 25.23 52958 1305.07 0.00 0 0.00 0 0 8 0 91 >> 0 184 127.48 434 54.03 0.00 0 0.00 0 0 5 0 95 >> 0 61 127.49 440 54.78 0.00 0 0.00 0 0 5 0 95 >> 0 61 127.75 445 55.52 0.00 0 0.00 0 0 5 0 95 >> 0 61 127.49 442 55.03 0.00 0 0.00 0 0 4 0 96 >> 0 61 127.49 436 54.28 0.00 0 0.00 0 0 5 0 95 >> 0 61 125.27 425 51.99 0.00 0 0.00 0 0 5 1 94 >> 0 61 118.14 393 45.34 0.00 0 0.00 0 0 3 0 97 >> >> average 54MB/s with or without hw.mpt.enable_sata_wc seted in >> loader.conf file. >> >> is it a normal speed for this adapter?! >> >> > > > I'm confused - you said in your first post you were getting 3MB/s, where > above you show something like 55MB/s. > > 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). > > 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. > > Eric > > Well, if he's using SATA (which I kinda assumed originally without asking) then queue depth isn't going to matter; the MPT driver has no interaction with how SATA NCQ operates, if he even has a rev of the LSI chip that supports NCQ at all. If he's using SAS, then queue depth will only be a minor factor, CAM is pretty good at autosizing the depth with minimal impact. Now, if he's using SAS disks then the boot tunable that I gave him will indeed have no impact at all. I believe that the Sun 4100 uses 2.5" disks, whether SATA or SAS. 54MB/s is not all that bad for disks of this size. It's pretty close to what I would expect, actually. Scott
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