Linux Handbook

This is simple unsorted various commands to quick remember useful Linux operation. You also can see hundred various recipes in this page - Linux.

1. Ubuntu server

• Open Firewall for WebServer


• Firewall rules order



• PermitRootLogin SSHD (sudo nano /etc/ssh/sshd_config,PertitLogin=yes,Service sshd restart, sudo passwd root)


• SCP Copy Over SSH


• Add Second User With The Same Home Contents


• List all service


• File permission - everyone can write file (-R recursive) sudo chmod u+rw,g+rw,o+rw tst1


• Ifconfig set IP anf gateway


• Ubuntu second IP


• Ubuntu 20 IP configuration (sudo nano /etc/netplan/00-installer-config.yaml)



• Disk manipulating - lsblk, fdisk, mkfs, /etc/fstab, mount, raid



• Increase swap



• Lvm info



• IO monitoring (sudo apt install sysstat, watch iostat -x)



• Network monitoring iftop, Iptraf-ng, cat /proc/net/vlan, bmon, dstat

2. CentOS server

• List device and mount cdrom

• List device and mount cdrom


• Network diagnostic (nslookup, wget, mtr, route, ifconfig, resolv.config, etc/hosts, ethtool, ftp upload)


• SSL diagnostic (openssl s_client -debug -cipher ALL -servername github.com -connect github.com:443), github, generate ssh key, add key yo ssh client

3. Other

• Allow Ftp transfer Special Chars to filenames


• mRemoteNG ShowPass


• FF PortBlocked

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