GFS file systems that have been mounted manually rather than automatically through an entry in the
fstab file will not be known to the system when file systems are unmounted at system shutdown. As a result, the GFS script will not unmount the GFS file system. After the GFS shutdown script is run, the standard shutdown process kills off all remaining user processes, including the cluster infrastructure, and tries to unmount the file system. This unmount will fail without the cluster infrastructure and the system will hang.
To prevent the system from hanging when the GFS file systems are unmounted, you should do one of the following:
Always use an entry in the
fstab file to mount the GFS file system.
If a GFS file system has been mounted manually with the
mount command, be sure to unmount the file system manually with the
umount command before rebooting or shutting down the system.
If your file system hangs while it is being unmounted during system shutdown under these circumstances, perform a hardware reboot. It is unlikely that any data will be lost since the file system is synced earlier in the shutdown process.