• -.slice — the root slice;
• system.slice — the default place for all system services;
• user.slice — the default place for all user sessions;
• machine.slice — the default place for all virtual machines and Linux containers.

# systemd-cgls
# systemd-cgtop

# systemctl -t slice

Available Controllers in Red Hat Enterprise Linux 7

• blkio — sets limits on input/output access to and from block devices;
• cpu — uses the CPU scheduler to provide cgroup tasks an access to the CPU. It is mounted together with the cpuacct controller on the same mount;
• cpuacct — creates automatic reports on CPU resources used by tasks in a cgroup. It is mounted together with the cpu controller on the same mount;
• cpuset — assigns individual CPUs (on a multicore system) and memory nodes to tasks in a cgroup;
• devices — allows or denies access to devices for tasks in a cgroup;
• freezer — suspends or resumes tasks in a cgroup;
• memory — sets limits on memory use by tasks in a cgroup, and generates automatic reports on memory resources used by those tasks;
• net_cls — tags network packets with a class identifier (classid) that allows the Linux traffic controller (the tc command) to identify packets originating from a particular cgroup task;
• perf_event — enables monitoring cgroups with the perf tool;
• hugetlb — allows to use virtual memory pages of large sizes, and to enforce resource limits on these pages.

# systemctl set-property <unit-name> <parameter>=<value>
# systemctl set-property httpd.service CPUShares=600 MemoryLimit=500M
# systemctl set-property --runtime httpd.service CPUShares=600 MemoryLimit=500M # temporary change 

Änderungen an schon bestehenden Units werden persistent!

*Weight*: default=100. [10-10000]. 100 ist „die Mitte“