SysVinit to Systemd Cheatsheet Linux服务配置
1. fedora 15 开始使用systemd代替原来的sysv init了，对比下systemd下systemctl和原来的service，chkconfig。
http://fedoraproject.org/wiki/SysVinit_to_Systemd_Cheatsheet
还有一篇简单介绍systemd，和简单命令的使用的文章：http://fedoraproject.org/wiki/Systemd#Why_systemd.3F
2. Ubuntu下用sysv-rc-conf配置服务，可以用命令，也有ncurse的界面，配置方便；
SysVinit to Systemd Cheatsheet
This is a document to help system administrators who need to understand what commands in systemd replace their old workflow in sysvinit. If you want general information on systemd, refer tosystemd.
Note that the 'service' and 'chkconfig' commands will mostly continue to work as expected in the systemd world, this guide is how to use the native systemctl replacements.
Services
| sysvinit Command | systemd Command | Notes |
|---|---|---|
| service frobozz start | systemctl start frobozz.service | Used to start a service (not reboot persistent) |
| service frobozz stop | systemctl stop frobozz.service | Used to stop a service (not reboot persistent) |
| service frobozz restart | systemctl restart frobozz.service | Used to stop and then start a service |
| service frobozz reload | systemctl reload frobozz.service | When supported, reloads the config file without interrupting pending operations. |
| service frobozz condrestart | systemctl condrestart frobozz.service | Restarts if the service is already running. |
| service frobozz status | systemctl status frobozz.service | Tells whether a service is currently running. |
| ls /etc/rc.d/init.d/ | ls /lib/systemd/system/*.service /etc/systemd/system/*.service systemctl list-units --all |
Used to list the services that can be started or stopped Used to list all the services and other units |
| chkconfig frobozz on | systemctl enable frobozz.service | Turn the service on, for start at next boot, or other trigger. |
| chkconfig frobozz off | systemctl disable frobozz.service | Turn the service off for the next reboot, or any other trigger. |
| chkconfig frobozz | systemctl is-enabled frobozz.service | Used to check whether a service is configured to start or not in the current environment. |
| chkconfig frobozz --list | ls /etc/systemd/system/*.wants/frobozz.service | Used to list what levels this service is configured on or off |
| chkconfig frobozz --add | systemctl daemon-reload | Used when you create a new service file or modify any configuration |
Note that all /sbin/service and /sbin/chkconfig lines listed above continue to work on systemd, and will be translated to native equivalents as necessary. The only exception is chkconfig --list.
In SysVinit, services can define arbitrary commands. Examples would be service iptables panic, orservice httpd graceful. Native systemd services do not have this ability.
Any service that defines an additional command in this way would need to define some other, service-specific, way to accomplish this task when writing a native systemd service definition.
Check the package-specific release notes for any services that may have done this.Runlevels/targets
Systemd has a concept of targets which serve a similar purpose as runlevels but act a little different. Eachtarget is named instead of numbered and is intended to serve a specific purpose. Sometargets are implemented by inheriting all of the services of another target and adding additional services to it. There are systemdtargets that mimic the common sysvinit runlevels so you can still switchtargets using the familiartelinit RUNLEVEL command. The runlevels that are assigned a specific purpose on vanilla Fedora installs; 0, 1, 3, 5, and 6; have a 1:1 mapping with a specific systemdtarget. Unfortunately, there's no good way to do the same for the user-defined runlevels like 2 and 4. If you make use of those it is suggested that you make a new named systemdtarget as/etc/systemd/system/$YOURTARGET that takes one of the existing runlevels as a base (you can look at/lib/systemd/system/graphical.target as an example), make a directory/etc/systemd/system/$YOURTARGET.wants, and then symlink the additional services that you want to enable into that directory. (The service unit files that you symlink live in/lib/systemd/system).
| sysvinit Runlevel | systemd Target | Notes |
|---|---|---|
| 0 | runlevel0.target, poweroff.target | Halt the system. |
| 1, s, single | runlevel1.target, rescue.target | Single user mode. |
| 2, 4 | runlevel2.target, runlevel4.target, multi-user.target | User-defined/Site-specific runlevels. By default, identical to 3. |
| 3 | runlevel3.target, multi-user.target | Multi-user, non-graphical. Users can usually login via multiple consoles or via the network. |
| 5 | runlevel5.target, graphical.target | Multi-user, graphical. Usually has all the services of runlevel 3 plus a graphical login. |
| 6 | runlevel6.target, reboot.target | Reboot |
| emergency | emergency.target | Emergency shell |
Changing runlevels:
| sysvinit Command | systemd Command | Notes |
|---|---|---|
| telinit 3 | systemctl isolate multi-user.target (OR systemctl isolate runlevel3.target OR telinit 3) | Change to multi-user run level. |
| sed s/^id:.*:initdefault:/id:3:initdefault:/ | ln -sf /lib/systemd/system/multi-user.target /etc/systemd/system/default.target | Set to use multi-user runlevel on next reboot. |