Yesterday I saw a customer report for a failure of our application and it seemed at first a disk space issue. however, file system problems are generally something that applications cannot workaround.
Here the file system was a NFS mount even though it had the label of a GPFS mount. Further disk space was not an issue. Yet the application reported that it could not proceed because the open/read/write was failing. Mount showed the file system mount point and the remote server it mapped to. Since the mount was for a remote file system, we needed to check both the network connectivity and the file system read and writes.
A simple test that was suggested was to
Try writing a file outside the application with the dd utility to the remote server
Something like
dd -if /dev/zero -of /remotefs/testfile -b blocksize
And if that succeeds, read it back again as follows:
dd -if /remotefs/testfile -of /etc/null -b blocksize
With a round trip like that, the file system problems
could be detected.
The same diagnostics can be made part of the application diagnostics.