Install Ubuntu Server

UBUNTU SERVER

• Prefer older LTS (as more tested & pkgs supported)

• Only command line by default, must install GUI separately

• Download Link

• Add GUI

• Partition SetUp

  • Along with root (prefer SSD), swap, boot, home - var can also partitioned (so that logs doesn't take up normal space)
  • Advantages of using LVM instead Physical partitions link //snapshots

20.04 IMAGES & Partition

• Language

• Keyboard

• Network connection
  • choose network (no image as testing on machine without internet)

• Choose custom storage layout

• Consider 500GB hard disk laptop example.
  • All space made as available by deleting existing partitions.
  • Consider below sample with no allocation of drives

• Create a volume group

• Select entire disk partition for that group

• Create logical volume in that group

• Specify root logical volume for OS & softwares storage

  • choose ext4 (linux format)
  • mount to /

• Specify swap volume for extra RAM shortage space

  • typically 2*RAM size
  • Format - swap

• Similarly create my-boot volume

  • typically 1 GB as per initial partition suggestion link
  • choose ext4 (linux format)
  • Mount it to /boot

• Create my-home volume

  • choose remaining space
  • choose ext4 (linux format)
  • Mount it to /home

• Final volume look

• On GPT disks as mentioned in Partition SetUp link, we have to choose a boot disk. Current laptop has EFI partition.

  • Just choose the remaining specific partition & click on 'use as boot device'
  • For other styles, check Partition SetUp link

• click done

• profile setup (same user name & password are later used for login)

• Choose SSH access

• Click Reboot now

• Remove your pen drive/ CD & hit enter (else re-initiates installation after restart)

• Login With user name & pass

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Image references

DNS server

• to properly add DNS server don't change /etc/resolve.conf directly
• ref

//install package

sudo apt update

sudo apt install resolvconf

• open file "/etc/resolvconf/resolv.conf.d/head", add following

# Make edits to /etc/resolvconf/resolv.conf.d/head.

nameserver 8.8.4.4

nameserver 8.8.8.8

• restart service

sudo service resolvconf restart

Ethernet Issue

(If internet not auto detected) network-configuration

• add nameserver in '/etc/resolv.conf' file

//example

nameserver 192.*.*.*

nameserver 8.8.8.8 //google DNS server

nameserver 127.*.*.*

• Configure ethernet in /etc/network/interfaces or /etc/netplan

• In '/etc/netplan' following content

01-netcfg.yaml

• In '/etc/netplan/01-netcfg.yaml' following content

network:

version: 2

renderer: networkd

ethernets:

eno1:

addresses: [ 10.10.*.*/* ]

gateway4: 10.10.*.*

Note : Check 'ip a' to find ethernets or 'sudo lshw -class network' for detailed ethernet

Sample dynamic ip addressing

'/etc/netplan/99_config.yaml' file

network:

version: 2

renderer: networkd

ethernets:

enp3s0:

dhcp4: true

later

sudo netplan apply

Sample static ip

'/etc/netplan/99_config.yaml' file

network:

version: 2

renderer: networkd

ethernets:

eth0:

addresses:

- 10.10.10.2/24

gateway4: 10.10.10.1

nameservers:

search: [mydomain, otherdomain]

addresses: [10.10.10.1, 1.1.1.1]

later

sudo netplan apply

Sample static ip 2

'/etc/netplan/99_config.yaml' file

network:

version: 2

renderer: networkd

ethernets:

enp0s8: //check by "ip a"

addresses: [192.168.56.101/24]

dhcp4: false

later

sudo netplan apply

Change default ports

• default ssh

Note : openssh-server/ openssh-client package must be installed

/etc/ssh

//open port

sudo ufw allow {port}/tcp

//edit file

sudo vi /etc/ssh/sshd_config

//add following line

Port {port}

//restart ssh service

sudo systemctl restart sshd

//To verify that SSH daemon is listening on the new port

ss -an | grep {port}

// to connect from client

ssh -p {port} {username}@{remote_host_or_ip}

• to Disable password based SSH, check command-security.md

Create system restore points

• time shift