Re: ZFS with Linux: An Open Plea

David Chinner
2007-04-16T03:07:18Z

On Sun, Apr 15, 2007 at 08:50:25PM -0400, Rik van Riel wrote:
> David R. Litwin wrote:
>
> >>4: ZFS has a HUGE capacity. I don't have 30 exobytes, but I might some
> >>day....
> >
> >ext4 will probably cope with that. XFS definitely has very high
> >limits though I admit I don't know what they are.
> >
> >XFS is also a few exobytes.
>
> The fsck for none of these filesystems will be able to deal with
> a filesystem that big. Unless, of course, you have a few weeks
> to wait for fsck to complete.

Which is why I want to be able to partially offline a chunk of
a filesystem and repair it while the rest is still online.....

> Backup and restore are similar problems. When part of the filesystem
> is lost, you don't want to have to wait for a full restore.
>
> Sounds simple? Well, the hard part is figuring out exactly which
> part of the filesystem you need to restore...
>
> I don't see ZFS, ext4 or XFS addressing these issues.

XFS has these sorts of issues directly in our cross-hairs.

The major scaling problem XFS has right now is to do with
how long repair/backup/restore take when you have hundreds
of terabytes of storage.

> IMHO chunkfs could provide a much more promising approach.

Agreed, that's one method of compartmentalising the problem.....

Cheers,

Dave.
--
Dave Chinner
Principal Engineer
SGI Australian Software Group