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From: "JaniD++" <djani22@dynamicweb.hu>
To: linux-raid@vger.kernel.org
Subject: RAID0 performance question
Date: Sat, 26 Nov 2005 15:04:37 +0100	[thread overview]
Message-ID: <015c01c5f292$57e0e270$0400a8c0@dcccs> (raw)
In-Reply-To: 20051122220531.GU26862@skl-net.de

Hello list,

I have searching the bottleneck of my system, and found something what i
cant cleanly understand.

I have use NBD with 4 disk nodes. (raidtab is the bottom of mail)

The cat /dev/nb# >/dev/null    makes ~ 350 Mbit/s on each nodes.
The cat /dev/nb0 + nb1 + nb2 + nb3 in one time parallel makes ~ 780-800
Mbit/s. - i think this is my network bottleneck.

But the cat /dev/md31 >/dev/null (RAID0, the sum of 4 nodes) only makes
~450-490 Mbit/s, and i dont know why....

Somebody have an idea? :-)

(the nb31,30,29,28 only possible mirrors)

Thanks
Janos

raiddev         /dev/md1
raid-level      1
nr-raid-disks   2
chunk-size      32
persistent-superblock 1
device          /dev/nb0
raid-disk       0
device          /dev/nb31
raid-disk       1
failed-disk     /dev/nb31

raiddev         /dev/md2
raid-level      1
nr-raid-disks   2
chunk-size      32
persistent-superblock 1
device          /dev/nb1
raid-disk       0
device          /dev/hb30
raid-disk       1
failed-disk     /dev/nb30

raiddev         /dev/md3
raid-level      1
nr-raid-disks   2
chunk-size      32
persistent-superblock 1
device          /dev/nb2
raid-disk       0
device          /dev/nb29
raid-disk       1
failed-disk     /dev/nb29

raiddev         /dev/md4
raid-level      1
nr-raid-disks   2
chunk-size      32
persistent-superblock 1
device          /dev/nb3
raid-disk       0
device          /dev/nb28
raid-disk       1
failed-disk     /dev/nb28

raiddev         /dev/md31
raid-level      0
nr-raid-disks   4
chunk-size      32
persistent-superblock 1
device          /dev/md1
raid-disk       0
device          /dev/md2
raid-disk       1
device          /dev/md3
raid-disk       2
device          /dev/md4
raid-disk       3



  reply	other threads:[~2005-11-26 14:04 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-11-18 19:34 mdadm 2.1: command line option parsing bug? Andreas Haumer
2005-11-21 23:21 ` Neil Brown
2005-11-22 11:21   ` Michael Tokarev
2005-11-24  5:15     ` Neil Brown
2005-11-22 15:41   ` Molle Bestefich
2005-11-24  5:25     ` Neil Brown
2005-11-24  7:31       ` Ross Vandegrift
2005-12-15  1:53       ` Molle Bestefich
2005-12-15  4:19         ` Neil Brown
2005-12-15 10:37           ` Molle Bestefich
2005-11-22 22:05   ` Andre Noll
2005-11-26 14:04     ` JaniD++ [this message]
2005-11-26 15:56       ` RAID0 performance question Raz Ben-Jehuda(caro)
2005-11-26 16:08         ` JaniD++
2005-11-26 17:11           ` Lajber Zoltan
2005-11-26 17:34             ` JaniD++
2005-11-26 19:47               ` Lajber Zoltan
2005-11-26 23:27       ` Neil Brown
2005-11-26 23:37         ` JaniD++
2005-11-27 15:39         ` Al Boldi
2005-11-27 16:21           ` JaniD++
2005-11-27 17:40             ` Al Boldi
2005-11-27 19:02               ` JaniD++
2005-11-30 23:13               ` JaniD++
2005-12-02 19:53                 ` Al Boldi
2005-12-18  0:13                   ` JaniD++
2005-12-19 11:16                     ` Al Boldi
2005-11-22  1:14                       ` JaniD++
2005-11-23 10:48                       ` JaniD++
2005-12-21  1:40                     ` Neil Brown
2005-11-22  1:56                       ` JaniD++
2005-12-22  4:49                         ` Neil Brown
2005-11-23  9:44                           ` JaniD++

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