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From: "JaniD++" <djani22@dynamicweb.hu>
To: Al Boldi <a1426z@gawab.com>
Cc: linux-raid@vger.kernel.org
Subject: Re: RAID0 performance question
Date: Thu, 1 Dec 2005 00:13:37 +0100	[thread overview]
Message-ID: <041e01c5f605$6a7c0830$0400a8c0@dcccs> (raw)
In-Reply-To: 200511272040.47644.a1426z@gawab.com

Hello,

> > > > > 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? :-)
> > > >
> > > > Try increasing the read-ahead setting on /dev/md31 using 'blockdev'.
> > > > network block devices are likely to have latency issues and would
> > > > benefit from large read-ahead.
> > >
> > > Also try larger chunk-size ~4mb.
> >
> > Ahh.
> > This is what i can't do. :-(
> > I dont know how to backup 8TB! ;-)
>
> Maybe you could use your mirror!?

I have one idea! :-)

I can use the spare drives in the disknodes! :-)

But i don't know exactly what to try.
increase or decrease the chunksize?
In the top layer raid (md31,raid0) or in the middle layer raids (md1-4,
raid1) or both?

Can somebody help me to find the performance problem source?

Thanks,
Janos


>
> --
> Al


  parent reply	other threads:[~2005-11-30 23:13 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     ` RAID0 performance question JaniD++
2005-11-26 15:56       ` 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++ [this message]
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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