RFC: using ceph as a backend for an NFSv4.1 pNFS server

[Rick Macklem]

Ivan Voras wrote:
> On 26/04/2014 21:47, Rick Macklem wrote:
> 
> > Any other comments w.r.t. this would be appreciated, including
> > generic stuff like "we couldn't care less about pNFS" or technical
> > details/opinions.
> > 
> > Thanks in advance for any feedback, rick
> > ps: I'm no where near committing to do this at this point and
> >     I do realize that even completing the ceph port to FreeBSD
> >     might be beyond my limited resources.
> 
> What functionality from ceph would pNFS really need? Would pNFS need
> to
> be implemented with a single back-end storage like ceph or could it
> be
> modular? (I don't have much experience here but it looks like HDFS is
> becoming popular for some big-data applications).
> 
> 
>From a quick glance, HDFS (Hadoop) uses a weak consistency model and
is designed for write once, read many files. (It does not appear to
be POSIX compliant.) Swift sounds somewhat similar, in that it has
a "eventually consistent" rule.

I'll take a closer look at it, but at first glance it doesn't sound
like it would be appropriate as a back end to a pNFS server. (pNFS
clients expect to see what they get from NFS, except they can do the
reads/writes other ways.)

Thanks everyone for the comments so far, rick


rick