How to manage shared persistent local caching (FS-Cache) with NFS?

[David Howells]

Jon Masters <jonathan at jonmasters.org> wrote:

> I think the shared superblock approach is the right one, but I'm a
> little concerned that there would now be different behavior for fscache
> and non-cached setups. Not sure of any better idea though.

The behaviour varies a bit anyway because there's a cache...

> > The R/O mount flag can be dealt with by moving readonlyness into the
> > vfsmount rather than having it a property of the superblock.  The
> > superblock would then be read-only only if all its vfsmounts are also
> > read-only.
> 
> Given that, how many connection parameters are there that are likely to
> actually differ on the same client, talking to the same server? Really?

I don't have figures on that, but I do know people have complained about it
for non-cached conditions.

> You could store the table in a NIS map, for example, and a udev rule or
> similar could trigger to load it later.

My point was meant to be that the presence and coverage of a cache is more
likely to reflect the client machine than would the NIS map for the NFS
automounts.  You wouldn't necessarily want to store this table in NIS.

David