2.12. Unloading Control Groups
cgclearcommand destroys all cgroups in all hierarchies. If you do not have these hierarchies stored in a configuration file, you will not be able to readily reconstruct them.
To clear an entire cgroup file system, use the
All tasks in the cgroup are reallocated to the root node of the hierarchies, all cgroups are removed, and the file system itself is unmounted from the system, destroying all previously mounted hierarchies. Finally, the directory where the cgroup file system was mounted is removed.
mountcommand to create cgroups (as opposed to creating them using the
cgconfigservice) results in the creation of an entry in the
/etc/mtabfile (the mounted file systems table). This change is also reflected in the
/proc/mountsfile. However, the unloading of cgroups with the
cgclearcommand, along with other cgconfig commands, uses a direct kernel interface which does not reflect its changes into the
/etc/mtabfile and only writes the new information into the
/proc/mountsfile. After unloading cgroups with the
cgclearcommand, the unmounted cgroups can still be visible in the
/etc/mtabfile, and, consequently, displayed when the
mountcommand is executed. Refer to the
/proc/mountsfile for an accurate listing of all mounted cgroups.