Understanding the cgroup filesystem
On any system that runs cgroups, you'll see a cgroup directory under the /sys/fs/ virtual filesystem, as shown here:
[donnie@localhost ~]$ cd /sys/fs [donnie@localhost fs]$ ls -ld cgroup/ drwxr-xr-x. 14 root root 360 Jul 3 15:52 cgroup/ [donnie@localhost fs]$
As with all virtual filesystems, the cgroup filesystem only exists in memory at runtime and disappears when you shut down the machine. There's no permanent copy of it on the machine's drive.
When you look inside the /sys/fs/cgroup/ directory, you'll see something like this:
Figure 11.3 – cgroupfs on Alma Linux
Each of these directories represents a cgroup susbsystem. (You'll also see them referred to as either controllers or resource controllers.) Inside each of these directories is a set of files that represent the cgroup's tunables. These files hold information about any resource control or tuning parameters...