Ceph » CephFS

IOR depends on mpi. mpich2 is pretty easy to set up (there's a package).

I think an ior task would need to:
- take a list of clients
- push a machine list to a 'master' node that starts the job (probably not where teuth itself is running)
- set up a temp ssh key so they can connect to each other (or we could make this part of the teuth worker config?)
- set up a symlink on each client so that a single path (/tmp/cephtest/sharedmnt.0 or something) gets you into the mount point on all machines
- download the ior tarball, compile and build it (needs to build with mpicc, which requires mpich2 be installed)
- run ior with whatever parameters the task specifies.

Might make sense to make a generic 'mpi' task that sets up the mpi environment, and separate that from the ior bits.

SamL has done some work on getting MPI going under teuthology, and on running some multi-client FS tests. I'm not sure what the status of that work is, but whoever does this bug will need to check into that.