After some low level SAS expander firmware updates on our JetStor shelves, the lustre filesystem is reporting several zero length files. The raids show normal status, and all OSTs mount on the OSS nodes w/o problems. The clients also mount the filesystem. Read/write tests from the clients report no errors, but several files which had content before are showing up zero length. These files appear to be on different OSTs so it's not on any particular shelf. Rebooting the servers and a few clients hasn't shown any change. Servers are running CentOS 5.5, lustre 1.8.3. Could low level disk settings cause lustre to report zero length files? There have been no software changes on these systems, so not sure what could be causing this. Any thoughts? Thanks, -Anjana Kar Pittsburgh Supercomputing Center kar-YUCGctl3KYs@public.gmane.org