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From: Neil Brown <neilb@suse.de>
To: Jon Nelson <jnelson-linux-raid@jamponi.net>
Cc: linux-raid@vger.kernel.org
Subject: RE:  RAID 6 grow problem
Date: Wed, 6 Jun 2007 10:46:00 +1000	[thread overview]
Message-ID: <18022.968.613733.320715@notabene.brown> (raw)
In-Reply-To: message from Jon Nelson on Tuesday June 5

On Tuesday June 5, jnelson-linux-raid@jamponi.net wrote:
> 
> I have an EPoX 570SLI motherboard with 3 SATAII drives, all 320GiB: one 
> Hitachi, one Samsung, one Seagate. I built a RAID5 out of a partition 
> carved from each. I can issue a 'check' command and the rebuild speed 
> hovers around 70MB/s, sometimes up to 73MB/s, and dstat/iostat/whatever 
> confirms that each drive is sustaining approximately 70MB/s reads. 
> Therefore, 3x70MB/s = 210MB/s which is a bunch more than 133MB/s. lspci 
> -v reveals, for one of the interfaces (the others are pretty much the 
> same):

...
> 
> I'm trying to determine what the limiting factor of my raid is: Is it 
> the drives, ....

If look at the data sheets for the drives (I just had a look at a
Seagate one, fairly easy to find on their web site) you should fine
the Maximum Sustained Transfer Rate, which will be about 70MB/s for
current 7200rpm drives.

So I think the drive is the limiting factor.

NeilBrown

  reply	other threads:[~2007-06-06  0:46 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <Pine.LNX.4.64.0706021232040.13184@p34.internal.lan>
2007-06-02 21:26 ` RAID 6 grow problem Iain Rauch
2007-06-02 21:31   ` Justin Piszcz
2007-06-02 21:33     ` Justin Piszcz
2007-06-02 21:38   ` Neil Brown
2007-06-02 21:55     ` Iain Rauch
2007-06-02 22:07       ` Neil Brown
2007-06-02 22:35         ` Iain Rauch
2007-06-03 23:33           ` Daniel Korstad
2007-06-04  6:47             ` RAID6 clean? Guy Watkins
2007-06-04  6:59               ` Neil Brown
2007-08-18  5:40                 ` Guy Watkins
2007-06-04 20:29           ` RAID 6 grow problem Bill Davidsen
2007-06-05 17:08             ` Iain Rauch
2007-06-05 19:21               ` Daniel Korstad
2007-06-05 21:26                 ` Jon Nelson
2007-06-06  0:46                   ` Neil Brown [this message]
2007-06-10 19:18                 ` Iain Rauch
2007-06-10 20:17                   ` Justin Piszcz
2007-06-06 15:06 Daniel Korstad
2007-06-06 15:38 ` Jon Nelson
2007-06-07  4:44   ` Neil Brown
  -- strict thread matches above, loose matches on Subject: below --
2007-06-02 15:30 Iain Rauch
2007-06-02 16:19 ` Justin Piszcz

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