Filesets - usage errors

The misunderstandings while dealing with the filesets and the courses of action to correct them.

These are common mistakes and misunderstandings that are encountered when dealing with filesets:

Fileset junctions look very much like ordinary directories, but they cannot be deleted by the usual commands, such as rm -r or rmdir command. By using these commands on a fileset junction can result in a Not owner message on an AIX® system, or an Operation not permitted message on a Linux® system.
As a consequence these commands might fail when applied to a directory that is a fileset junction. Similarly, when the rm -r command is applied to a directory that contains a fileset junction, it fails as well.

On the other hand, the rm -r command deletes all the files that are contained in the filesets that are linked under the specified directory. Use the mmunlinkfileset command to remove fileset junctions.
Files and directories are moved from one fileset to another, or a hard link cross fileset boundary.
If the user is unaware of the locations of fileset junctions, then the mv and ln commands might fail unexpectedly. In most cases, the mv command automatically compensates for this failure and uses a combination of cp and rm to accomplish the desired result. Use the mmlsfileset command to view the locations of fileset junctions. Use the mmlsattr -L command to determine the fileset for any given file.
Because a snapshot saves the contents of a fileset, deleting a fileset that is included in a snapshot cannot completely remove the fileset.
The fileset is put into a 'deleted' state and continues to appear in the mmlsfileset command output. Once the last snapshot that is containing the fileset is deleted, the fileset is automatically removed. The mmlsfileset --deleted command indicates deleted filesets and shows their names in parentheses.
Deleting a large fileset might take some time and might be interrupted by other failures, such as disk errors or system crashes.
When this occurs, the recovery action leaves the fileset in a being deleted state. Such a fileset might not be linked into the namespace. The corrective action it to finish the deletion by reissuing the fileset delete command:
```
mmdelfileset fs1 fsname1 -f
```
The mmlsfileset command identifies filesets in this state by displaying a status of 'Deleting'.
If you unlink a fileset that has other filesets that are linked below it, then any filesets that are linked to it (that is, child filesets) becomes inaccessible. The child filesets remain linked to the parent and becomes accessible again when the parent is relinked.
By default, the mmdelfileset command does not delete a fileset that is not empty.
To empty a fileset, first unlink all its immediate child filesets to remove their junctions from the fileset to be deleted. Then, while the fileset itself is still linked, use the rm -rf or a similar command to remove the rest of the contents of the fileset. Now the fileset might be unlinked and deleted. Alternatively, the fileset to be deleted can be unlinked first and then the mmdelfileset command can be used with the -f (force) option. This unlinks its child filesets, then deletes the files and directories that are contained in the fileset.
When a small dependent fileset is deleted, it might be faster to use the rm -rf command instead of the mmdelfileset command with the -f option.