On Tue, 1 Sep 2009, Jpd wrote:
Thanks.
Any idea on how to work out which one.
I can't find smart in ips, so what other ways are there?
You could try using a script like this one to find pokey disks:
#!/bin/ksh
# Date: Mon, 14 Apr 2008 15:49:41 -0700
# From: Jeff Bonwick <jeff.bonw...@sun.com>
# To: Henrik Hjort <hj...@dhs.nu>
# Cc: zfs-discuss@opensolaris.org
# Subject: Re: [zfs-discuss] Performance of one single 'cp'
#
# No, that is definitely not expected.
#
# One thing that can hose you is having a single disk that performs
# really badly. I've seen disks as slow as 5 MB/sec due to vibration,
# bad sectors, etc. To see if you have such a disk, try my diskqual.sh
# script (below). On my desktop system, which has 8 drives, I get:
#
# # ./diskqual.sh
# c1t0d0 65 MB/sec
# c1t1d0 63 MB/sec
# c2t0d0 59 MB/sec
# c2t1d0 63 MB/sec
# c3t0d0 60 MB/sec
# c3t1d0 57 MB/sec
# c4t0d0 61 MB/sec
# c4t1d0 61 MB/sec
#
# The diskqual test is non-destructive (it only does reads), but to
# get valid numbers you should run it on an otherwise idle system.
disks=`format </dev/null | grep ' c.t' | nawk '{print $2}'`
getspeed1()
{
ptime dd if=/dev/rdsk/${1}s0 of=/dev/null bs=64k count=1024 2>&1 |
nawk '$1 == "real" { printf("%.0f\n", 67.108864 / $2) }'
}
getspeed()
{
# Best out of 6
for iter in 1 2 3 4 5 6
do
getspeed1 $1
done | sort -n | tail -2 | head -1
}
for disk in $disks
do
echo $disk `getspeed $disk` MB/sec
done
--
Bob Friesenhahn
bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/
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