The darshan-parser output for log files generated on Hopper will sometimes show UNKNOWN for the mount point and fs type. This only happens for files that are not opened on rank 0. The problem does not appear in globally shared files, or files at rank 0.

Closer inspection of the log file indicates that the CP_DEVICE field is set to zero. Preliminary test runs that print the CP_DEVICE field at the time that the file is opened indicate that it is correct, however. Maybe the data is being corrupted when adjusting that field to match device IDs detected at rank 0?

Another observation is that this is occurring for files opened on the $SCRATCH (Lustre) file system on Hopper, which has an unusually large device ID of 3592384858.

Need to find a simpler test case and determine if this problem is present on Beagle as well.