Searching log for shutdown/reboot on Linux

To address problem, sometimes, we need to find log to know machine's shutdown/reboot time. However, how to do it?

last command

We use command, man last, to view the illustration(link). It lists login account, but reboot the machines use a pseudo account. Hence, we use the command, last reboot , to show the reboot time. For an instance, it shows last reboot time at 5/12 13:04.

[root@centos-6 ~]# last reboot
reboot   system boot  2.6.32-431.el6.x Thu May 12 13:04 - 12:29 (3+23:25)   
reboot   system boot  2.6.32-431.el6.x Mon May  9 09:55 - 13:01 (3+03:05)   
reboot   system boot  2.6.32-431.el6.x Thu Apr 14 18:20 - 09:52 (24+15:31)  
reboot   system boot  2.6.32-431.el6.x Thu Apr 14 15:00 - 18:19  (03:19)    
reboot   system boot  2.6.32-431.el6.x Thu Apr 14 14:42 - 14:59  (00:16)    
reboot   system boot  2.6.32-431.el6.x Thu Apr 14 14:31 - 14:42  (00:10)    
reboot   system boot  2.6.32-431.el6.x Thu Apr 14 14:27 - 14:30  (00:03)    
reboot   system boot  2.6.32-431.el6.x Thu Apr 14 14:20 - 14:26  (00:05)     
reboot   system boot  2.6.32-431.el6.x Tue Jan 26 14:12 - 14:28  (00:15)    
reboot   system boot  2.6.32-431.el6.x Tue Jan 26 13:47 - 14:11  (00:24)    
reboot   system boot  2.6.32-431.el6.x Tue Jan 26 13:35 - 13:46  (00:10)    
reboot   system boot  2.6.32-431.el6.x Tue Jan 26 11:50 - 13:35  (01:45)    
reboot   system boot  2.6.32-431.el6.x Tue Jan 26 11:18 - 11:49  (00:31)    
reboot   system boot  2.6.32-431.el6.x Tue Jan 26 11:10 - 11:18  (00:07)    
reboot   system boot  2.6.32-431.el6.x Tue Jan 26 10:48 - 11:10  (00:21)    
reboot   system boot  2.6.32-431.el6.x Tue Jan 26 10:10 - 10:48  (00:37)    

wtmp begins Tue Jan 26 09:57:17 2016

Then if you want to list logs of shutdown. Using the command, last -x shutdown, which is follows.

[root@centos-6 ~]# last -x shutdown
shutdown system down  2.6.32-431.el6.x Thu May 12 13:01 - 13:04  (00:02)    
shutdown system down  2.6.32-431.el6.x Mon May  9 09:52 - 09:55  (00:03)    
shutdown system down  2.6.32-431.el6.x Thu Apr 14 18:19 - 18:20  (00:00)    
shutdown system down  2.6.32-431.el6.x Thu Apr 14 14:59 - 15:00  (00:00)    
shutdown system down  2.6.32-431.el6.x Thu Apr 14 14:42 - 14:42  (00:00)    
shutdown system down  2.6.32-431.el6.x Thu Apr 14 14:31 - 14:31  (00:00)    
shutdown system down  2.6.32-431.el6.x Thu Apr 14 14:26 - 14:27  (00:00)    
shutdown system down  2.6.32-431.el6.x Tue Jan 26 13:46 - 13:47  (00:00)    
shutdown system down  2.6.32-431.el6.x Tue Jan 26 13:35 - 13:35  (00:00)    
shutdown system down  2.6.32-431.el6.x Tue Jan 26 11:49 - 11:50  (00:00)    
shutdown system down  2.6.32-431.el6.x Tue Jan 26 11:18 - 11:18  (00:00)    
shutdown system down  2.6.32-431.el6.x Tue Jan 26 11:10 - 11:10  (00:00)    
shutdown system down  2.6.32-431.el6.x Tue Jan 26 10:48 - 10:48  (00:00)    
shutdown system down  2.6.32-431.el6.x Tue Jan 26 10:09 - 10:10  (00:00) 

wtmp begins Tue Jan 26 09:57:17 2016