Date: Tue, 21 Sep 1999 11:20:56 +0930 From: Greg Lehey <grog@lemis.com> To: Chad David <davidc@lodge.guild.ab.ca> Cc: FreeBSD Hackers <hackers@freebsd.org> Subject: Re: SCSI vs IDE with vinum Message-ID: <19990921112056.T55065@freebie.lemis.com> In-Reply-To: <Pine.BSF.4.05.9908211058020.6190-100000@lodge.guild.ab.ca>; from Chad David on Sat, Aug 21, 1999 at 11:46:18AM -0600 References: <Pine.BSF.4.05.9908211058020.6190-100000@lodge.guild.ab.ca>
next in thread | previous in thread | raw e-mail | index | archive | help
[Format recovered--see http://www.lemis.com/email/email-format.html] On Saturday, 21 August 1999 at 11:46:18 -0600, Chad David wrote: > I just setup vinum for the first time on a brand new server, > nd I am getting what I think are strange results in performance > tests with rawio. My SCSI drives seem to be much slower that my > IDE drives? > > wdc0 at 0x1f0-0x1f7 irq 14 flags 0xb0ffb0ff on isa > wdc0: unit 0 (wd0): <IBM-DTTA-371440>, LBA, DMA, 32-bit, multi-block-16 > wd0: 13783MB (28229040 sectors), 1757 cyls, 255 heads, 63 S/T, 512 B/S > wdc0: unit 1 (wd1): <IBM-DTTA-371440>, LBA, DMA, 32-bit, multi-block-16 > wd1: 13783MB (28229040 sectors), 1757 cyls, 255 heads, 63 S/T, 512 B/S > wdc1 at 0x170-0x177 irq 15 flags 0xb0ffb0ff on isa > wdc1: unit 0 (wd2): <IBM-DTTA-371440>, LBA, DMA, 32-bit, multi-block-16 > wd2: 13783MB (28229040 sectors), 1757 cyls, 255 heads, 63 S/T, 512 B/S > wdc1: unit 1 (wd3): <IBM-DTTA-371440>, LBA, DMA, 32-bit, multi-block-16 > wd3: 13783MB (28229040 sectors), 1757 cyls, 255 heads, 63 S/T, 512 B/S > da0 at ahc0 bus 0 target 3 lun 0 > da0: <IBM DNES-318350W SA30> Fixed Direct Access SCSI-3 device > da0: 40.000MB/s transfers (20.000MHz, offset 8, 16bit), Tagged Queueing Enabled > da0: 17501MB (35843670 512 byte sectors: 255H 63S/T 2231C) > da1 at ahc0 bus 0 target 6 lun 0 > da1: <IBM DNES-318350W SA30> Fixed Direct Access SCSI-3 device > da1: 40.000MB/s transfers (20.000MHz, offset 8, 16bit), Tagged Queueing Enabled > da1: 17501MB (35843670 512 byte sectors: 255H 63S/T 2231C) > > ########################################################################## > > As you can see there are four 14.4 Gig IBM IDE drives, and 2 > 18Gig IBM SCSI drives. > > My vinum config is: > > drive scsi1 device /dev/da0e > drive scsi2 device /dev/da1e > drive ide1 device /dev/wd2e > drive ide2 device /dev/wd3e You'd get better performance spreading your volume across two IDE controllers. Since you have a wd1 as well, you might consider swapping wd1 and wd3. > volume exporthome > plex org concat > sd length 0 drive scsi1 > sd length 0 drive scsi2 > > volume backup > plex org concat > sd length 0 drive ide1 > sd length 0 drive ide2 > > SCSI > # rawio -a -v 1 /dev/vinum/rexporthome > Test ID K/sec /sec %User %Sys %Total > RR anon 1774.1 110 0.1 0.7 0.7 16384 > SR anon 14482.7 884 0.1 5.3 5.4 16384 > RW anon 1573.7 98 0.1 0.6 0.6 16384 > SW anon 1981.8 121 0.0 0.7 0.8 16384 > > /dev/rda0 is one of the raw drives in exporthome.. > # rawio -a -v 1 /dev/rda0 > Test ID K/sec /sec %User %Sys %Total > RR anon 2241.3 138 0.1 0.5 0.6 16384 > SR anon 19115.9 1167 0.1 4.5 4.5 16384 > RW anon 959.1 60 0.0 0.2 0.3 16384 > SW anon 2608.7 159 0.0 0.6 0.6 16384 > > > IDE > # rawio -a -v 1 /dev/vinum/rbackup > Test ID K/sec /sec %User %Sys %Total > RR anon 1372.9 86 0.0 0.4 0.4 16384 > SR anon 28443.2 1736 0.4 7.5 7.8 16384 > RW anon 601.3 37 0.0 0.2 0.2 16384 > SW anon 12227.7 746 0.3 3.1 3.4 16384 > > /dev/rwd1 is just a stand alone IDE drive. > # rawio -a -v 1 /dev/rwd1 > Test ID K/sec /sec %User %Sys %Total > RR anon 1610.0 100 0.0 0.2 0.3 16384 > SR anon 28828.8 1760 0.4 3.3 3.7 16384 > RW anon 1218.5 76 0.1 0.2 0.2 16384 > SW anon 11628.1 710 0.0 1.5 1.5 16384 > > I could be wrong but shouldn't the SCSI system blow away the IDE system? Not necessarily. This is a common fallacy. But the performance figures you're getting there don't look very good. I wonder if the SCSI drives have some problem. On the other hand, the serial throughput on wd1 looks surprisingly high. > On a side note, can you enable softupdates on a vinum fs? Yes. Vinum is just a virtual disk. Greg -- See complete headers for address, home page and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?19990921112056.T55065>