Boot
The Linux system performs the boot process automatically when the system is turned on. There a series of messages that display during this process. If there are problems, error messages will display.
The scripts used to control how the system will work are stored in the /etc directory. Mainly /etc/inittab and /etc/rc.d. You can view these files but we strongly recommend that you not attempt to change them unless you are an experienced Linux administrator.
Shutdown
Linux, like any server operating system, does not like it if you just turn the power off. You risk the possibilities of damaging the operating system. Before turning the power off, you must execute the ‘shutdown‘ command.
| Options | What it does |
|---|---|
| now | shutdown immediately |
| +n | n is the number of minutes to wait |
| -h | actually halt system, ready for power off |
| -r | shutdown and automatically perform a re-boot |
| -c | cancel the shutdown |
| Examples | What it does |
|---|---|
| shutdown now -h | To shutdown the system immediately, ready for power off |
| shutdown +10 -h | To shutdown the system in 10 minutes and ready for power off |
| shutdown now -r or reboot | To shutdown and automatically reboot |
INIT
If the system is already up and running, you can use the init command to start/stop the status of the system.
| Options | What it does |
|---|---|
| 0 | halt system |
| 1 | single user mode (for maintenance purposes, won’t allow others to login) |
| 3 | multi-user mode (normal mode) |
| 5 | multi-user mode with GUI started (normal level for workstations using Xwindows) |
| 6 | reboot |
| Examples | What it does |
|---|---|
| init 1 | To set single user mode |
| init 6 | reboot |
Cleaning the File System
fsck
is automatically run every time the system boots. Occasionally you may have to run fsck manually to fix a damaged file system. Because the results and options can vary greater, it is recommended to only run this utility with the advice of an Linux administrator. Must be run from the root account.