When creating a GFS Shared File System using a partition of an existing file system, be aware of the following important information.
To use a partition that is already in use by an existing GFS Shared File System for a new GFS Shared File System, delete the existing file system and then create the new file system.
See
For information about deleting a file system, see "11.8 Deleting."
To use a partition that is in use by a file system other than the GFS Shared File System, unmount the file system on all nodes and then delete in accordance with the procedure for that file system. Also, delete the definition in /etc/fstab and then create the GFS Shared File System.