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From: Phil Dier <phil@icglink.com>
To: linux-kernel@vger.kernel.org
Cc: ziggy <ziggy@icglink.com>, Jack Massari <jack@icglink.com>,
	Scott Holdren <scott@icglink.com>
Subject: Slow I/O with SMP, Fusion-MPT and u160 SCSI JBOD
Date: Wed, 14 Sep 2005 15:01:09 -0500	[thread overview]
Message-ID: <20050914150109.232c6765.phil@icglink.com> (raw)

Hi,

I just tried the 2.6.14-rc1 kernel to see if it exhibits the behaviour
I have described before[0]. It still does. Briefly, I have a dual Xeon
2.8 with 4GB ram, 1 adaptec and 1 fusion-mpt scsi device, each connected
to 1 SCSI JBOD with 5 disks apiece[1]. I/O on scsi ids 0 and 1 both
work flawlessly. I built an md device across ids 2 and 3, and the disks
connected to the fusion-mpt are unbearably slow. This behaviour was not
present in 2.6.12.3.  When I partition the devices in question and mount
a filesystem on them, they exhibit the same behaviour individually.

[0]: http://www.ussg.iu.edu/hypermail/linux/kernel/0508.3/1233.html
[1]: http://www.icglink.com/debug-2.6.14-rc1.html


Here is what iostat looks like during what should be heavy I/O (my
tesh.sh script described in [1] is running), showing only the relevant
devices:


$ iostat 1 -k | awk '/(Device|md5|md6|md7)/{print $0;}'
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.62         0.00         2.46        244     198312
md6               0.62         0.00         2.46        228     198312
md7               0.61         0.01         2.45        440     197856
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5              25.74         0.00       102.97          0        104
md6              25.74         0.00       102.97          0        104
md7               9.90         0.00        39.60          0         40
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5              59.41         0.00       237.62          0        240
md6              60.40         3.96       237.62          4        240
md7              20.79         3.96        79.21          4         80
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5             100.99         0.00       403.96          0        408
md6             100.99         0.00       403.96          0        408
md7              72.28         0.00       289.11          0        292
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5           16242.57         0.00     64970.30          0      65620
md6           16242.57         0.00     64970.30          0      65620
md7           16230.69         0.00     64922.77          0      65572
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5            1014.85         0.00      4059.41          0       4100
md6            1014.85         0.00      4059.41          0       4100
md7            1014.85         0.00      4059.41          0       4100
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5            3298.02         0.00     13192.08          0      13324
md6            3298.02         0.00     13192.08          0      13324
md7            3298.02         0.00     13192.08          0      13324
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5            2789.11         0.00     11156.44          0      11268
md6            2789.11         0.00     11156.44          0      11268
md7            2789.11         0.00     11156.44          0      11268
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
md5               0.00         0.00         0.00          0          0
md6               0.00         0.00         0.00          0          0
md7               0.00         0.00         0.00          0          0


Thanks for looking. Please cc me on replies.

-- 

Phil Dier (ICGLink.com -- 615 370-1530 x733)

/* vim:set noai nocindent ts=8 sw=8: */

             reply	other threads:[~2005-09-14 20:01 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-09-14 20:01 Phil Dier [this message]
2005-09-14 20:55 ` Slow I/O with SMP, Fusion-MPT and u160 SCSI JBOD John Stoffel
2005-09-14 21:41 ` Mark Lord
2005-09-14 21:58   ` Phil Dier
2005-09-14 22:08   ` Phil Dier

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