Re: topics for the file system mini-summit

[Andreas Dilger <adilger@clusterfs.com>]

On May 26, 2006  20:49 -0400, Ric Wheeler wrote:
> Andreas Dilger wrote:
> >In a way what you describe is Lustre - it aggregates multiple "smaller"
> >filesystems into a single large filesystem from the application POV
> >(though in many cases "smaller" filesystems are 2TB).  It runs e2fsck
> >in parallel if needed, has smart object allocation (clients do delayed
> >allocation, can load balance across storage targets, etc), can run with
> >down storage targets.
>
> The approach that lustre takes here is great -  distributed systems 
> typically  take into account subcomponent failures as a fact of life & 
> do this better than many single system designs...
> 
> The challenge is still there on the "smaller" file systems that make up 
> Lustre - you can spend a lot of time waiting for just one fsck to finish ;-)

CFS is actually quite interested in improving the health and reliability
of the component filesystems also.  That is the reason for our interest
in the U. Wisconsin IRON filesystem work, which we are (slowly) working
to include into ext3.

This will also be our focus for upcoming filesystem work.  It is
relatively easy to make filesystems with 64-bit structures, but the
ability to run such large filesystems in the face of corruption
environments is the real challenge.  It isn't practical to need a
17-year e2fsck time, extrapolating 2TB e2fsck times to 2^48 block
filesystems.  A lot of the features in ZFS make sense in this regard.

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