1. Service units, which start and control daemons and the processes they consist of.
   For details, see systemd.service(5).
2. Socket units, which encapsulate local IPC or network sockets in the system, useful for socket-based activation. 
   For details about socket units, see systemd.socket(5)
   For details on socket-based activation and other forms of activation, see daemon(7).
3. Target units are useful to group units, or provide well-known synchronization points during boot-up.
4. Device units expose kernel devices in systemd and may be used to implement device-based activation.
   For details, see systemd.device(5).
5. Mount units control mount points in the file system.
   For details see systemd.mount(5).
6. Automount units provide automount capabilities, for on-demand mounting of file systems as well as parallelized boot-up. 
   See systemd.automount(5).
7. Timer units are useful for triggering activation of other units based on timers. 
   See systemd.timer(5).
8. Swap units are very similar to mount units and encapsulate memory swap partitions or files of the operating system. 
   See systemd.swap(5).
9. Path units may be used to activate other services when file system objects change or are modified. 
   See systemd.path(5).
10. Slice units may be used to group units which manage system processes (such as service and scope units) in a hierarchical tree for resource management purposes. 
    See systemd.slice(5).
11. Scope units are similar to service units, but manage foreign processes instead of starting them as well. 
    See systemd.scope(5).


The New Control Group Interfaces中介绍了systemd和cgroup的关系,以及如何systemd管理的进程的cgroup。


service: 由systemd通过.service文件启动创建的进程
scopes:  任意一个进程创建的进程,被通过dbus接口注册到了PID1
slices:  slices中包含service、scopes或者继续包含slices




systemctl set-property httpd.service CPUShares=500 MemoryLimit=500M


  1. man systemd
  2. man systemd.unit
  3. man systemd.resource-control
  4. The New Control Group Interfaces
  5. man systemd.service
  6. man systemd.socket
  7. man daemon
  8. man
  9. man systemd.device
  10. man systemd.mount
  11. man systemd.automount
  12. man systemd.timer
  13. man systemd.swap
  14. man systemd.path
  15. man systemd.slice
  16. man systemd.scope
  17. man systemd.special



Copyright @2011-2019 All rights reserved. 转载请添加原文连接,合作请加微信lijiaocn或者发送邮件: [email protected],备注网站合作

友情链接:  李佶澳的博客  小鸟笔记  软件手册  编程手册  运营手册  网络课程  课程文档  精选文章  发现知识星球  百度搜索 谷歌搜索