From: Brad Campbell <brad@wasp.net.au>
To: Guy <bugzilla@watkins-home.com>
Cc: 'Stephan van Hienen' <raid@a2000.nu>, linux-raid@vger.kernel.org
Subject: Re: raid5 code ok with 2TB + ?
Date: Sun, 28 Nov 2004 23:20:12 +0400 [thread overview]
Message-ID: <41AA24EC.5020206@wasp.net.au> (raw)
In-Reply-To: <200411281819.iASIJmN00402@www.watkins-home.com>
Guy wrote:
> Your 2.2T array is not as big as you think!
>
> 1TB = 2^40 not 1*10^12
> Maybe depending on if you are buying disk drives, or selling them! :)
> But when related to the 2TB limit it is 2^40.
>
> 2206003968 blocks
> Divide by 1024 gives you 2154300.75 meg
> Divide by 1024 gives you 2103.8093 Gig
> Divide by 1024 gives you 2.0545 TB
> So you are just over 2TB. by 58520320 blocks or 55.8 Gig.
>
> The only reason I am being exact is that you have not tested disk I/O beyond
> 2TB as much as you think. Once, someone else made a similar 2T claim, after
> the math he was really below 2T.
Fair call. Having said that, if the code wrapped at 2TB then I would have blown away the 1st 55.8
Gig of my partition, which would be enough to prove the code faulty :p)
--
Brad
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Burn a Greenie. X AGAINST HTML MAIL
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next prev parent reply other threads:[~2004-11-28 19:20 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-11-28 10:48 raid5 code ok with 2TB + ? Stephan van Hienen
2004-11-28 10:57 ` Brad Campbell
2004-11-28 11:19 ` Stephan van Hienen
2004-11-28 11:28 ` Brad Campbell
2004-11-28 18:19 ` Guy
2004-11-28 19:20 ` Brad Campbell [this message]
2004-11-28 20:17 ` raid5 code ok with 2TB + ? NEGATIVE :( Stephan van Hienen
2004-11-28 20:27 ` Stephan van Hienen
2004-11-28 20:45 ` Stephan van Hienen
2004-11-28 23:34 ` raid5 code ok with 2TB + ? Stephan van Hienen
2004-11-29 4:49 ` Guy
2004-11-29 8:33 ` Stephan van Hienen
2004-11-29 8:51 ` raid5 slow Stephan van Hienen
2004-11-29 17:13 ` Guy
2004-11-29 18:11 ` Stephan van Hienen
2004-11-30 0:06 ` raid5 slow (looks like 2.6 problem) Stephan van Hienen
2004-11-30 0:30 ` raid5 slow Neil Brown
2004-11-30 0:50 ` Stephan van Hienen
2004-11-30 19:37 ` Stephan van Hienen
2004-11-30 23:26 ` Neil Brown
2004-11-30 23:39 ` Stephan van Hienen
2004-11-30 23:55 ` Stephan van Hienen
2004-12-01 19:23 ` raid5 slow (test on another system) Stephan van Hienen
2004-12-01 22:21 ` Stephan van Hienen
2004-12-02 22:01 ` Stephan van Hienen
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