Bug 769874

Description of problem:
"tail" from coreutils is trying to use inotify with the FhGFS remote file system, which isn't working (i.e. a process will not receive inotify notifications when a file is updated by a process on another machine in a cluster).

Steps to reproduce:
1. Use "tail -f" on a log file from machine A in an FhGFS mount directory.
2. Append text to the log file from machine B.
3. "tail -f" will not show/notice that the file has been updated, because it is waiting for an inotify notification (which won't be coming).
  
Actual results:
"tail -f" does not show updates, although the file has in fact been updated.

Expected results:
"tail -f" should fallback to the stat-based polling method instead of using inotify on a remote file system. Then it would work as expected and show/notice that the file has been updated.

Additional info:
Most of our users are using RHEL and thus currently experience problems when they try to watch their compute job log files with "tail -f" on a cluster.

Tail has an internal list of remote file systems, for which it automatically disables inotify. I already reported the problem to the GNU coreutils mailing list and a small patch has been developed by Jim Meyering to add FhGFS to tail's list of remote file systems, which resolves the problem:
http://lists.gnu.org/archive/html/bug-coreutils/2011-12/msg00129.html

To resolve the problem for our users as quickly as possible, can you please apply the patch to the RHEL version of the GNU coreutils.

Thanks and best regards,

Sven Breuner
Fraunhofer HPC, FhGFS Development Team