Repair-driven file system design (was Re: ZFS with Linux: An Open Plea)

[Valerie Henson <val_henson@linux.intel.com>]

On Mon, Apr 16, 2007 at 01:07:05PM +1000, David Chinner wrote:
> On Sun, Apr 15, 2007 at 08:50:25PM -0400, Rik van Riel wrote:
>
> > IMHO chunkfs could provide a much more promising approach.
> 
> Agreed, that's one method of compartmentalising the problem.....

Agreed, the chunkfs design is only one way to implement repair-driven
file system design - designing your file system to make file system
check and repair fast and easy.  I've written a paper on this idea,
which includes some interesting projections estimating that fsck will
take 10 times as long on the 2013 equivalent of a 2006 file system,
due entirely to changes in disk hardware.  So if your server currently
takes 2 hours to fsck, an equivalent server in 2013 will take about 20
hours.  Eek!  Paper here:

http://infohost.nmt.edu/~val/review/repair.pdf

While I'm working on chunkfs, I also think that all file systems
should strive for repair-driven design.  XFS has already made big
strides in this area (multi-threading fsck for multi-disk file
systems, for example) and I'm excited to see what comes next.

-VAL