Hi Lorenzo, > I realize that flock and other flavors of advisory locking are not > officially supported by PVFS through VFS. However, with my setup of one > PVFS client machine, four I/O servers, and one metadata server > (different from the client machine), it does appear that multiple > applications and/or threads, on the one client machine, calling flock on > a pvfs2 file-system file behave correctly. This can be tested using the > (FC5) flock application. As expected, this does not work with multiple > client machines.
A generic flock() mechanism is implemented in the VFS layer fs/locks.c. Network file systems that allow clients to run on other physically separate machines require more code than what the VFS layer does to serialize readers.writers on a single node. We havent done that yet for PVFS and hence it wont work on multiple client nodes as you indicate below. > Now the question: Is the behavior I'm observing by design, or is it > some coincidence that should not be relied upon. So it should work as long as they are all threads/processes on the same machine/running on the same kernel. Thanks, Murali _______________________________________________ Pvfs2-users mailing list [email protected] http://www.beowulf-underground.org/mailman/listinfo/pvfs2-users
