From: Andreas Dilger <adilger@clusterfs.com>
To: Jim Cromie <jim.cromie@gmail.com>
Cc: kernel learner <kernellearner@gmail.com>,
linux-fsdevel@vger.kernel.org, kernelnewbies@nl.linux.org
Subject: Re: Upgrading datastructures between different filesystem versions
Date: Wed, 26 Sep 2007 10:17:56 -0600 [thread overview]
Message-ID: <20070926161756.GU32520@schatzie.adilger.int> (raw)
In-Reply-To: <46F9F0EB.6020404@gmail.com>
On Sep 25, 2007 23:40 -0600, Jim Cromie wrote:
> kernel learner wrote:
> >ext3 filesystem has 32-bit block address and ext4 filesystem has
> >48-bit block address. If a user installs ext4, how will the file
> >system handle already existing block with 32 bit values?
>
> Why should it ? thats what ext3 is for.
Bzzt. Wrong answer. The ext4 code will be able to read existing ext3
(and ext2) filesystems just fine. Otherwise there wouldn't be much
of an upgrade path.
> Id expect ext4 drivers handling ext3 filesystems is a distant, secondary
> goal to getting a fast, reliable, clean 48bit filesystem working.
Far from the truth. One of the main goals of ext4 is that it is a drop-in
replacement for ext3. The code is mostly incremental improvements over
ext3, and that IS one of the reasons that it is reliable. We didn't throw
away 10 years of bug fixes in the ext2/ext3 code when adding the ext4
features.
Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.
next prev parent reply other threads:[~2007-09-26 16:17 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-25 15:27 Upgrading datastructures between different filesystem versions kernel learner
2007-09-26 5:40 ` Jim Cromie
2007-09-26 16:17 ` Andreas Dilger [this message]
2007-09-26 23:29 ` Sachin Gaikwad
2007-09-27 0:53 ` Theodore Tso
2007-09-28 13:11 ` Erik Mouw
2007-09-28 13:31 ` Christoph Hellwig
2007-09-28 19:47 ` Theodore Tso
2007-09-29 9:05 ` Christoph Hellwig
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