How To: Use Some Useful Commands¶

This doc will go over certain useful commands you may use on the infrastructure.

System Commands¶

View System Stats¶

If you want to view CPU & RAM usage, active processes, and system uptime, run the following command:

Bash

top -i
# -i will hide any inactive processes.

It will look something like this:

Text Only

top - 11:52:41 up 57 days,  3:13,  1 user,  load average: 0.24, 0.20, 0.13
Tasks: 194 total,   1 running, 193 sleeping,   0 stopped,   0 zombie
%Cpu(s):  0.5 us,  0.7 sy,  0.8 ni, 97.6 id,  0.0 wa,  0.0 hi,  0.1 si,  0.3 st
MiB Mem :  16002.8 total,  14226.2 free,    905.5 used,    871.0 buff/cache
MiB Swap:      0.0 total,      0.0 free,      0.0 used.  14757.2 avail Mem

    PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
███████ netdata   ██  ██  ██████ ██████  █████ █   3.3   1.2 290:45.66 netdata

Item	Meaning
`up`	Show uptime in days
`Tasks`	Lists the total amount, running, sleeping, stopped and 'zombie' tasks
`%CPU(s)`	CPU utilisations
`MiB Mem`	Shows the total, free, used, and cached memory in KibiBytes (MiB)
`MiB Swap`	Shows the total, free, use, and available Swap ⧉ memory.

Column	Meaning
`PID`	Process ID
`USER`	User that started the process
`PR`	Process Priority
`NI`	'Nice' value, another priority value
`VIRT`	Virtual Memory Size in KibiBytes (KiB)
`RES`	Resident Memory Size in KibiBytes (KiB)
`SHR`	Shared Memory Size in KibiBytes (KiB)
`S`	Process Status. ('D' = Uninterruptable sleep, 'R' = Running, 'S' = Sleeping, 'T' = Traced / Stopped, 'Z' = Zombie)
`%CPU`	CPU Utilisation in Percentage
`%MEM`	Memory Utilisation in Percentage
`TIME+`	Total CPU time used by the process, in hundredths of a second
`COMMAND`	The command used to start the process

Restarting a Server¶

When you want to restart a server, run the following command:

Bash

sudo shutdown -r now
# -r tells it to restart
# now tells it to do it immediately

You will be instantly disconnected as the server shuts down and restarts.

A restart may take a few minutes, so do be patient!

After a restart, follow the restart / unexpected shutdown checklist!