InterMezzo persistent file cache - a way to go?

[hanzl at noel.feld.cvut.cz]

Did any of you try InterMezzo network filesystem?

  http://www.inter-mezzo.org

I spent weekend in their docs and the design seems very well
engineered - it could often work over network with speed of local ext3
filesystem for both read and write (!). It filters requests to normal
ext3 serving as a persistent cache, working directly with local
filesystem on cache hits and syncing over network otherwise, with
clever use of journals.

It is yet in development but quite close to usable, so I thing some
attention (and little help ;-) from people on this list could greatly
push it forward.

Documents need to be updated here and there, code should be finished
and debugged, but it still seemes to be very good way to go if you
want persistent file cache.

And yes, I thing many people here want persistent file cache, as many
people have harddisk in their nodes and this harddisk is much much
faster then Fast Ethernet NIC which also many of us still use.

There are 'hevy' projects like AFS and Coda; these also provide
persistent cache but are rather cumbersome (e.g. Coda uses its own
filesystem). There is Enhanced Disk-Caching NFS Implementation by Greg
Badros but it is unmaintained now.

The obvious idea of using local filesystem to cache files which are
otherwise fetched again and again seemes to have no easy available
lightweight opensource solution - until InterMezzo is finished.


There is reason for InterMezzo to be finished soon and maintained
well: It is quite appealing both to cluster people and to 'normal'
networked people as well - they can get much quicker and more robust
networked filesystem than NFS is. So we may have the 'commodity
software' effect - huge mainstream pushing us forward.

IMHO InterMezzo is now just missing wider publicity, more people
knowing that miracles offered by InterMezzo can come true soon - and
so <propaganda> shall we help it a bit? </propaganda>

Looking forward for any comments

Vaclav Hanzl

------------------

References:

InterMezzo Home:
 http://www.inter-mezzo.org

InterMezzo HOWTO:
 http://www.inter-mezzo.org/docs/InterSync-HOWTO.html

Old benchmarks suggesting that InterMezzo is needed:
 http://www.inter-mezzo.org/docs/bottlenecks.pdf

Design of current InterMezzo synchronization daemon intersync:
 http://www.inter-mezzo.org/docs/intersync.pdf

Happy articles about InterMezzo:
 http://www.linuxplanet.com/linuxplanet/reports/4368/1/
 http://www.byte.com/documents/s=2289/byt1010012679751/0107_moshe.html

Caching NFS Client [GJB98]:
 http://www.vergenet.net/linux/redundant_content/talk/html/node4.html
 http://www.cs.washington.edu/homes/gjb/doc/enhanced-linux-nfs-client/index.html