[OpenAFS] Caching of RW volumes

Derek Atkins warlord@MIT.EDU
Fri, 21 Apr 2006 12:35:54 -0400

Kristian Du <kristian@hitech-sanita.it> writes:

> Hi There,
> I was wondering whether afsd/openafs.ko performs any sort of caching of
> the files it fetches from RW volumes. And if it does, does it follow the
> same "rules" used for caching data fetched from RO volumes?
> I was planning to migrate /home on a AFS RW volume and I was worrying
> about an increase in data traffic on the network.

Yes, OpenAFS caches all data, regardless of whether it's readonly
or read-write.  For RW data, the cache manager maintains a callback
for each individual file, whereas readonly data only requires a callback
on the volume.  The fileserver will notify the clients when a file changes
so the client can pull down the new version on the next access.

       Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
       Member, MIT Student Information Processing Board  (SIPB)
       URL: http://web.mit.edu/warlord/    PP-ASEL-IA     N1NWH
       warlord@MIT.EDU                        PGP key available