When you are owning a server, a virtual private server or a dedicated server, you sure would want to know the availability of the server on the internet and how long it has been running.
One of the command to check this is called uptime. This command only works on unix or linux operating system.
To display the system uptime, invoke the command without any options ::
The output will show something like this :
22:20:33 up 620 days, 22:37, 1 user, load average: 0.03, 0.10, 0.10
22:20:33 is the current system time.
up 620 days, 22:37 is the length of time the system has been up.
1 user is the number of logged in users.
load average: 0.03, 0.10, 0.10 are system load averages for the past 1, 5, and 15 minutes.
The load average on Linux can be a little confusing. Unlike other operating systems that shows CPU load averages, Linux is showing system load averages.
System load average measurement of the number of jobs that are currently running or waiting for disk I/O. It basically tells you how busy your system has been over the given interval.
If the load averages are 0.0, then the system is mostly idle. If the load average for the past 1 minute is higher than the 5 or 15-minute averages, then the load is increasing, otherwise, the load is decreasing. The load average increases due to higher CPU consumption, disk workload.
The -p, –pretty option tells uptime to display the output in a pretty format:
The output will show only how long the system has been running:
up 1 year, 36 weeks, 4 days, 23 hours, 15 minutes
The -s, –since option shows the date and time since the system is up:
Hope this helps.