Tips for Linux Server Administration

I purchased a cheap refurbished Dell desktop recently to act as my home server - host my project apps, run CI/CD, and a database. This weekend I installed Ubuntu server on it, plugged in a hardwire connection to my router and fired her up.

System Resources and Processes

View running processes

htop

View Processor Info

cat /proc/cpuinfo

View memory info

cat /proc/meminfo

Filesystem

List available storage volumes

Tree listing of available storage

lsblk

Mount a Filesystem

This command will mount a filesystem temporarily:

sudo mount /dev/path/to/device /mnt/path/to/desired/mountpoint 

If you also want automatic mounting after a reboot we must edit the the fstab file by using this command:

sudo vi /etc/fstab

Once open, you can place your cursor on a new line of the file and specify the mount you want using this format:

/dev/sdb1 /mtn/data ext4 defaults 0 2

An explaination of the fields can be found on the fstab man page. In this example, we specify

1. source
2. target
3. filesystem type
4. mount option (defaults: rw, suid, dev, exec, auto, nouser, async)
5. speficy which filesystems need to be dumped (zero is default - don’t dump)
6. used to determine boot order. Root filesystem should be 1. If not root, should be 2.

System backup and restore

There’s a very good thread that describes how easy a Linux backup is. Unlike Windows, you can just copy over

tar cvpzf backup.tgz \
    --exclude=/proc \
    --exclude=/lost+found \
    --exclude=/backup.tgz \
    --exclude=/mnt \
    --exclude=/sys \
    /

Crontab

Bash

Sometimes you’ll want to append a date

#/bin/bash
now=$(date +"%m_%d_%Y")
echo "Filename : /nas/backup_$now.sql"

this will output as Filename : /nas/backup_04_27_2010.sql

Tmux

Working with Panes

Create a new pane to the right

Ctrl+b %

Create a new pane to the bottom

Ctrl+b "

Remove current pane

exit

Switch to left pane

Ctrl+b <-

Switch to right pane

Ctrl+b <-

Working with Windows

Create a new window

Ctrl+b c

Switch to another window

Ctrl+b 0

Attaching and detaching

Detach

Ctrl+b d

View running tmux sessions

tmux ls

Attach to session 0

tmux  attach -t 0

Rename session from 0 to git

tmux rename-session -t 0 git