Linux - Ubuntu 18.04 server setup debug

Few ubuntu server setup issues and corresponding steps to debug them.

1. Disabling floppy drive: Error: print_req_error: I/O error, dev fd0, sector 0

   1sudo rmmod floppy
   2sudo echo "blacklist floppy" | sudo tee /etc/modprobe.d/blacklist-floppy.conf
   3sudo dpkg-reconfigure initramfs-tools
   

2. Error: Network not up: eth/ens doesnt show or no service network-manager

    1sudo dhclient
    2sudo apt update
    3sudo apt install network-manager ifupdown
    4sudo service network-manager restart
    5sudo systemctl status NetworkManager.service
    6
    7sudo vi /etc/netplan/01-netcfg.yaml
    8     # This file describes the network interfaces available on your system
    9     # For more information, see netplan(5).
   10     network:
   11     version: 2
   12     renderer: NetworkManager
   13     ethernets:
   14         ens32:
   15         dhcp4: yes
   16sudo netplan generate
   17sudo netplan apply
   

3. ssh setup

   1## For regenerating only rsa key
   2sudo ssh-keygen -t rsa -b 4096 -f ssh_host_rsa_key
   3## For regenerating all missing keys
   4sudo ssh-keygen
   5# service ssh restart
   6sudo systemctl status ssh
   

4. Fix non-configured locales

   1sudo locale-gen en_US en_US.UTF-8
   2sudo dpkg-reconfigure locales