After reading the OSDI paper
(http://www.usenix.org/events/osdi06/tech/full_papers/weil...), Ceph tries
to solve a more general problem than GFS.
Note that this neither makes GFS nor Ceph better than the other.
Like many solutions to problems in distributed computing these days, GFS optimizes for
specific workloads (the Ceph authors claim "Similarly, the Google File System is optimized
for very large files and a workload consisting largely of reads and file appends." -- check
out section 8 of the OSDI paper for more comparisons).
In general, Ceph is a much conservative approach, wrt the file system interface. The claim is
that the FS exported by Ceph is general purpose, exposes POSIX file semantics, and performs
well across a wider variety of workloads. It will be hard to say whether this is *true*
(whatever that means) until it is used much more widely..
I made some comments on the Kernel Trap discussion of Ceph, but I'll repeat the high point
here: it's cool to see research software GPL'd and targeted toward a general audience.
There are quite a few interesting local and distributed filesystem projects going on right now
(meaning, ones that are attempting to be more than research vehicles). I look forward to
seeing btrfs, Hadoop's cluster FS, Ceph, and other projects which I have no doubt forgotten