Softupdates and the Metadata Problem?

[Farid Hajji]

Hi Marcus,

it was nice to meet you personally at the GUUG conference in Cologne last
week ;-). I thought a bit about the metadata problem that results in the
1 GB limit of ext2fs and ufs filesystems (and theoretically others as well).
I didn't find a solution yet (still pondering over/on the problem), but here
is something that could probably help:

In FreeBSD, softupdates are currently being developed/tested for UFS
filesystems. I'm not aware of the ext{2,3}fs efforts here, but looking
at ReiserFS or other journalled filesystems could be a good idea as well ;-).
If we managed to use a similar approach in the libdiskfs-based servers,
we could probably avoid having to map all metadata in virtual memory.
This is just a speculation; as I still have to read/study the papers and
code of softupdates and journalled filesystems. Anyone else on this list
familiar with this kind of filesystems? Any link appreciated.

The links to softupdates are:

  Abstract: http://www.mckusick.com/softdep/
  Paper   : http://www.ece.cmu.edu/~ganger/papers/CSE-TR-254-95/

Regards,

-Farid.

-- 
Farid Hajji -- Unix Systems and Network Admin | Phone: +49-2131-67-555
Broicherdorfstr. 83, D-41564 Kaarst, Germany  | farid.hajji@ob.kamp.net
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