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From: Andreas Dilger <adilger@clusterfs.com>
To: Andi Kleen <andi@firstfloor.org>
Cc: Kalpak Shah <kalpak@clusterfs.com>,
	linux-ext4 <linux-ext4@vger.kernel.org>,
	TheodoreTso <tytso@mit.edu>
Subject: Re: Random corruption test for e2fsck
Date: Wed, 11 Jul 2007 23:19:38 -0600	[thread overview]
Message-ID: <20070712051938.GD5586@schatzie.adilger.int> (raw)
In-Reply-To: <p73myy3x8z0.fsf@bingen.suse.de>

On Jul 11, 2007  17:20 +0200, Andi Kleen wrote:
> If you use a normal pseudo random number generator and print the seed
> (e.g. create from the time) initially the image can be easily recreated 
> later without shipping it around. /dev/urandom
> is not really needed for this since you don't need cryptographic
> strength randomness. Besides urandom data is precious and it's 
> a pity to use it up needlessly.
> 
> bash has $RANDOM built in for this purpose.

Except it is a lot more efficient and easy to do
"dd if=/dev/urandom bs=1k ..." than to spin in a loop getting 16-bit
random numbers from bash.  We would also be at the mercy of the shell
being identical on the user and debugger's systems.

I don't think that running this test once in a blue moon on some
system is going to be a source of problems.

Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.

  reply	other threads:[~2007-07-12  5:19 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-07-10 13:07 Random corruption test for e2fsck Kalpak Shah
2007-07-10 14:58 ` Theodore Tso
2007-07-10 15:42   ` Eric Sandeen
2007-07-11  7:03   ` Kalpak Shah
     [not found]   ` <20070711094410.GM6417@schatzie.adilger.int>
2007-07-11 17:43     ` Theodore Tso
2007-07-12  5:15       ` Andreas Dilger
2007-07-12  5:52   ` Andreas Dilger
2007-07-10 15:47 ` Eric Sandeen
2007-07-11 16:03   ` Andreas Dilger
2007-07-11 15:20 ` Andi Kleen
2007-07-12  5:19   ` Andreas Dilger [this message]
2007-07-12 11:09     ` Andi Kleen
2007-07-12 22:16       ` Andreas Dilger
2007-07-12 22:24         ` Andi Kleen
2007-07-13  7:12           ` Kalpak Shah

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