lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Fri, 27 Apr 2007 14:38:21 -0600
From:	Andreas Dilger <adilger@...sterfs.com>
To:	Valerie Clement <valerie.clement@...l.net>
Cc:	ext4 development <linux-ext4@...r.kernel.org>
Subject: Re: Large File Deletion Comparison (ext3, ext4, XFS)

On Apr 27, 2007  15:41 +0200, Valerie Clement wrote:
> As asked by Alex, I included in the test results the file fragmentation 
> level and the number of I/Os done during the file deletion.
> 
> Here are the results obtained with a not very fragmented 100-GB file:
> 
>                  |     ext3       ext4 + extents      xfs
> ------------------------------------------------------------
>  nb of fragments |     796             798             15
>  elapsed time    |  2m0.306s        0m11.127s       0m0.553s
>                  |
>  blks read       |  206600            6416            352
>  blks written    |   13592           13064            104
> ------------------------------------------------------------
> 
> 
> And with a more fragmented 100-GB file:
> 
>                  |     ext3       ext4 + extents       xfs
> ------------------------------------------------------------
>  nb of fragments |   20297           19841            234
>  elapsed time    | 2m18.914s        0m27.429s      0m0.892s
>                  |
>  blks read       |  225624           25432            592
>  blks written    |   52120           50664            872
> ------------------------------------------------------------
> 
> 
> More details on our web site:
> http://www.bullopensource.org/ext4/20070404/FileDeletion.html

Ah, one thing that is only mentioned in the URL is that the "IO count" is
in units of 512-byte sectors.  In the case of XFS doing logical journaling
this avoids a huge amount of double writes to the journal and then to the
filesystem.  I still think ext4 could do better than it currently does.

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

-
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ