Clustering filesystem for small files

I'm looking for a distributed filesystem which I could use for storing lots of small files (<1MB usually). What I want to get is:

• 2 servers which have the fs mounted themselves and mirror the data
• locking support (among reachable nodes)
• some kind of best-effort automatic resynchronisation after one node goes down and comes back again

What I mean by the resync is that, I'm ok with both servers doing read/write operations even if they split-brain. I'm also ok if a local process obtains a lock if the other host is not reachable. From the resync I expect only a file-level consistent view after a while - that is - if file x is modified on both nodes during a split-brain, I don't really care which one is available after they join again, as long as it's full file, not one block coming from node1 and another block from node2.

Is there a solution like that out there? I see that gluster has some problems with file locks (even in 3.1). I also noticed that OCFS2 will panic if both nodes split-brain. What other filesystem would allow me to do what I want?

I recommend excellent LizardFS and GfarmFS although I'm not sure how well they support locks.

Update 2019: MooseFS is an excellent choice. Can't recommend LizardFS any more because it is poorly maintained...

Gluster is another cluster filesystem, but I'm not sure how this works if one node fails

[MogileFS][2] is an open-source distributed filesystem that can handle many small files and is supposed to have no single point a failure. However I think this lacks locking support. Not sure if it would be feasible to implement locking at the app level instead of in the filesystem?

As I am a new user here I can't post a second hyperlink in an answer, but MogileFS will come up on Google

/edit: I see you only have two servers. Perhaps DRBD will do what you want?