Q. How do you find Linux system last reboot/shutdown date and time?
A. You can use “last” command which will display all the previous reboot date and time for the system. This picks the information from the /var/log/wtmp file.

Last command

Use last command to display listing of system last reboot time and date:

# last reboot -1

Output

reboot   system boot  2.6.18-274.12.1. Wed Dec 14 06:01

To display last shutdown date and time use following command:

# last -x | grep shutdown | head -1

Output

shutdown system down  2.6.18-274.12.1. Wed Dec 14 06:44

Who command

Use the “who -b” command which displays the last system reboot date and time

# who -b

Output

system boot  2011-12-14 06:44

The post How To View Linux Last Reboot / Shutdown Date And Time appeared first on lifeLinux: Linux Tips, Hacks, Tutorials, Ebooks.

shutdown command brings the system down in a secure way. All logged-in users are notified that the system is going down, and login is blocked. It is possible to shut the system down immediately or after a specified delay. All processes are first notified that the system is going down by the signal SIGTERM. This gives programs like vi the time to save the file being edited, mail and news processing programs a chance to exit cleanly, etc. shutdown does its job by signalling the init process, asking it to change the runlevel. Runlevel 0 is used to halt the system, runlevel 6 is used to reboot the system, and runlevel 1 is used to put to system into a state where administrative tasks can be performed; this is the default if neither the -h or -r flag is given to shutdown. To see which actions are taken on halt or reboot see the appropriate entries for these runlevels in the file /etc/inittab.(http://linux.about.com/od/commands/l/blcmdl8_shutdow.htm)

Shutdown the machine immediately

Type the following command as root

# shutdown -h now

Shutdown the machine with user defined message

# shutdown -h now 'Server is going down for replace old hardware'

Scheduling the shutdown

Example, schedule shutdown for 3 AM.

# shutdown -h 03:00

Schedule shutdown the system in 5 minutes

# shutdown -h +5

Reboot the machine immediately

# shutdowm -r now

Cancel a running shutdown

# shutdown -c

The post Linux Shutdown Command appeared first on lifeLinux: Linux Tips, Hacks, Tutorials, Ebooks.

Using last command to show listing of last reboot / shutdown date and time. Last command which searches back through the file /var/log/wtmp (or the file designated by the -f flag) and displays a list of all users logged in (and out) since that file was created. Names of users and tty’s can be given, in which case last will show only those entries matching the arguments. Names of ttys can be abbreviated, thus last 0 is the same as last tty0.

To show listing of last reboot, type the following command

# last reboot

Sample output

reboot   system boot  2.6.18-194.32.1. Wed May 25 09:52         (90+21:57)
reboot   system boot  2.6.18-194.32.1. Sat Apr 23 09:20         (122+22:28)
reboot   system boot  2.6.18-194.32.1. Mon Apr 18 14:13         (4+02:33)

wtmp begins Tue Apr  5 15:15:41 2011

To show listing of last shutdown, type the following command

# last -x | grep down

Sample output

shutdown system down  2.6.18-194.32.1. Fri Apr 22 16:46 - 07:50 (123+15:03)

Where
-x: Display the system shutdown entries and run level changes.

The post Listing Of Last Reboot / Shutdown Date And Time appeared first on lifeLinux: Linux Tips, Hacks, Tutorials, Ebooks.