From owner-freebsd-scsi Tue Oct 31 20:52:39 2000 Delivered-To: freebsd-scsi@freebsd.org Received: from thelab.hub.org (CDR20-53.accesscable.net [24.138.20.53]) by hub.freebsd.org (Postfix) with ESMTP id 97F2437B4C5 for ; Tue, 31 Oct 2000 20:52:34 -0800 (PST) Received: from localhost (scrappy@localhost) by thelab.hub.org (8.11.1/8.11.1) with ESMTP id eA14oaf04895; Wed, 1 Nov 2000 00:50:36 -0400 (AST) (envelope-from scrappy@hub.org) X-Authentication-Warning: thelab.hub.org: scrappy owned process doing -bs Date: Wed, 1 Nov 2000 00:50:36 -0400 (AST) From: The Hermit Hacker To: Tom Samplonius Cc: freebsd-scsi@freebsd.org Subject: Re: iostat: tps for SCSI drives ... In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Tue, 31 Oct 2000, Tom Samplonius wrote: > > On Tue, 31 Oct 2000, The Hermit Hacker wrote: > > > Okay, how do I read this: > > > > pgsql# camcontrol tags da0 -v > > (pass0:ahc0:0:0:0): dev_openings 41 > > (pass0:ahc0:0:0:0): dev_active 0 > > (pass0:ahc0:0:0:0): devq_openings 41 > > (pass0:ahc0:0:0:0): devq_queued 0 > > (pass0:ahc0:0:0:0): held 0 > > (pass0:ahc0:0:0:0): mintags 2 > > (pass0:ahc0:0:0:0): maxtags 255 > > I wonder why dev_openings is lower than maxtags? anything I can look at/check to find out? > > pgsql# camcontrol tags da1 -v > > (pass1:ahc0:0:1:0): dev_openings 1 > > (pass1:ahc0:0:1:0): dev_active 0 > > (pass1:ahc0:0:1:0): devq_openings 1 > > (pass1:ahc0:0:1:0): devq_queued 0 > > (pass1:ahc0:0:1:0): held 0 > > (pass1:ahc0:0:1:0): mintags 2 > > (pass1:ahc0:0:1:0): maxtags 255 > > Here dev_openings is 1, so that would mean that the kernel can't have > more than one pending command. Since it is a (crappy) Fijitsu drive, I > would expect that either the drive told that the kernel it won't queue > commands, or there is quirk entry that disables tags for this drive. > > > pgsql# iostat -n5 -t da 5 > > tty da0 da1 da2 cpu > > tin tout KB/t tps MB/s KB/t tps MB/s KB/t tps MB/s us ni sy in id > > 77083887 48.00 36 1.67 0.00 0 0.00 0.00 0 0.00 23 0 9 0 68 > > 0 9856 42.97 34 1.45 0.00 0 0.00 8.07 23 0.18 0 0 0 0 0 > > 0 9856 39.77 41 1.57 0.00 0 0.00 8.00 23 0.18 0 0 0 0 0 > > > > max/mintags aren't a problem ... I take it, from what I'm reading in the > > man page, the 'pending' is the dev_active field? So, there is nothing > > pending? > > > > The two drives in use above are: > > > > da0 at ahc0 bus 0 target 0 lun 0 > > da0: Fixed Direct Access SCSI-2 device > > da0: 80.000MB/s transfers (40.000MHz, offset 15, 16bit), Tagged Queueing Enabled > > da0: 8683MB (17783240 512 byte sectors: 255H 63S/T 1106C) > > da2 at ahc0 bus 0 target 2 lun 0 > > da2: Fixed Direct Access SCSI-2 device > > da2: 80.000MB/s transfers (40.000MHz, offset 63, 16bit), Tagged Queueing Enabled > > da2: 17431MB (35700480 512 byte sectors: 255H 63S/T 2222C) > > > > So, for the Seagate, according to Seagate, the avg seek time is 5.2ms ... > > so I should max out around 192.3 tps on that drive? I know, not set in > > stone, but a reasonable number to work with, right? And, from what I can > > tell about the Fujitso, they are running around 7ms, so ~142tps? > > > > Does this make sense? > > > > > > > > > > > > Marc G. Fournier ICQ#7615664 IRC Nick: Scrappy Systems Administrator @ hub.org primary: scrappy@hub.org secondary: scrappy@{freebsd|postgresql}.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message