From: Mirko Benz <mirko.benz@web.de>
To: mingz@ele.uri.edu
Cc: Neil Brown <neilb@cse.unsw.edu.au>,
Linux RAID <linux-raid@vger.kernel.org>
Subject: Re: RAID 5 write performance advice
Date: Fri, 26 Aug 2005 09:51:52 +0200 [thread overview]
Message-ID: <430ECA18.10405@web.de> (raw)
In-Reply-To: <1124988876.5552.59.camel@localhost.localdomain>
Hello,
We have created a RAID 0 for the same environment:
Personalities : [raid0] [raid5]
md0 : active raid0 sdi[7] sdh[6] sdg[5] sdf[4] sde[3] sdd[2] sdc[1] sdb[0]
1250326528 blocks 64k chunks
*** dd TEST ***
time dd if=/dev/zero of=/dev/md0 bs=1M
14967373824 bytes transferred in 32,060497 seconds (466847843 bytes/sec)
iostat 5 output:
avg-cpu: %user %nice %sys %iowait %idle
0,00 0,00 89,60 9,50 0,90
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
hda 0,00 0,00 0,00 0 0
sda 0,00 0,00 0,00 0 0
sdb 455,31 0,00 116559,52 0 581632
sdc 455,51 0,00 116540,28 0 581536
sdd 450,10 0,00 116545,09 0 581560
sde 454,11 0,00 116559,52 0 581632
sdf 452,30 0,00 116559,52 0 581632
sdg 454,71 0,00 116553,11 0 581600
sdh 453,31 0,00 116533,87 0 581504
sdi 453,91 0,00 116556,31 0 581616
sdj 0,00 0,00 0,00 0 0
sdk 0,00 0,00 0,00 0 0
sdl 0,00 0,00 0,00 0 0
sdm 0,00 0,00 0,00 0 0
sdn 0,00 0,00 0,00 0 0
md0 116556,11 0,00 932448,90 0 4652920
Comments: 466 MB / 8 = 58,25 MB/s which is about the same as a dd to a
single disk (58,5 MB/s). So the controller + I/O subsystem is not the
bottleneck.
Regards,
Mirko
next prev parent reply other threads:[~2005-08-26 7:51 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-08-24 8:24 RAID 5 write performance advice Mirko Benz
2005-08-24 12:46 ` Ming Zhang
2005-08-24 13:43 ` Mirko Benz
2005-08-24 13:49 ` Ming Zhang
2005-08-24 21:32 ` Neil Brown
2005-08-25 16:38 ` Mirko Benz
2005-08-25 16:54 ` Ming Zhang
2005-08-26 7:51 ` Mirko Benz [this message]
2005-08-26 14:26 ` Ming Zhang
2005-08-26 14:30 ` Ming Zhang
2005-08-26 15:29 ` Mirko Benz
2005-08-26 17:05 ` Ming Zhang
2005-08-28 23:28 ` Neil Brown
2005-09-01 19:44 ` djani22
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