Linux Command for Uptime

Uptime is the time a device, usually a server, is available, turned on and connected without interruption. Among Sysadmins the uptime of a server may be interesting to evaluate the components and configuration, for example, I have an old Slackware server with over 3 years of uptime without human intervention, showing evidence of Slackware stability.

The Linux command uptime is capable of showing the current time, the total uptime time, the quantity of logged in users and the average number of uninterrupted executed processes. This tutorial shows the few ways in which the command uptime allows to print the information.

Linux Command for Uptime

To begin run the command “uptime” without flags as shown in the screenshot below:

The first column shows the current time, the second column shows the system is up, the third column should the total uptime (the server was available without interruption for 8:56 hours when checked), the fourth column shows the  number of logged users, the load average.

Note: System  load  averages is the average number of processes that are either in a runnable or uninterruptible state.  A  process in  a runnable state is either using the CPU or waiting to use the CPU.  A process in uninterruptible state  is  waiting  for some  I/O access, eg waiting for disk.  The averages are taken over the three time intervals.  Load averages are not  normal‐ized  for the number of CPUs in a system, so a load average of1 means a single CPU system is loaded all the time while on  a4 CPU system it means it was idle 75% of the time. (source: https://linux.die.net/man/1/uptime).

To show since when was the device online without interruption (the uptime chronological origin) add the -s flag:

The last option given by the uptime command is -p and it shows the total of uptime.

Additional information on the uptime tool:

OPTIONS

-p, –pretty – show uptime in pretty format
-h, –help – display this help text and exit.
-s, –since – system up since, in yyyy-mm-dd HH:MM:SS format
-V, –version – display version information and exit

FILES
/var/run/utmp information about who is currently logged on
/proc  process information

The Linux command for uptime doesn’t have too much option, yet you can get additional descriptions of this tool on the man page or online at https://linux.die.net/man/1/uptime.

There are related commands recommended by uptime’s man page such as ps and top for which you can read Using ps command on linux or Top’s man page.

I hope you found this brief article on Linux Command for Uptime useful, thank you for reading it.