nixCraft - Linux and Unix tutorials for new and seasoned sysadmin

Linux iptables delete prerouting rule command

last updated February 18, 2020 in CentOS, Debian / Ubuntu, Iptables, Linux, RedHat and Friends, Suse

I am a new Linux server sysadmin. I need to delete the PREROUTING rule. How do I delete the prerouting rule on Linux server?

How to Install phpredis on CentOS 8 / RHEL 8

last updated February 15, 2020 in CentOS, Linux, Package Management, PHP, RedHat and Friends

How do I install PHP extension called phpredis (php-redis) for interfacing with Redis cluster on CentOS 8 or RHEL 8?

How to Undo in Vim / Vi text editor

last updated February 13, 2020 in Linux, UNIX, Vim

How do I undo a recent change in the vim text editor?

Ubuntu Install Tinc and Set Up a Basic VPN

last updated February 10, 2020 in Cryptography, Linux, Ubuntu Linux

How do I install Tinc and Set Up a Basic VPN on Ubuntu Linux 18.04/20.04 LTS server?

Ansible apt update all packages on Ubuntu / Debian Linux

last updated February 7, 2020 in Debian / Ubuntu, Linux, Package Management, Ubuntu Linux

I have a bunch of servers powered by Ubuntu and Debian Linux. How do I update all of them using the apt module of Ansible? How can I use Ansible for system updates and reboot the box when kernel upgrades took place?

Linux extend file system after resize disk volume

last updated February 4, 2020 in CentOS, Debian / Ubuntu, File system, Linux, Ubuntu Linux

I increased the size of the volume in Linux using my cloud service providers’ online tool. My original disk size was 200GB, and I grew to 400GB. However, I only able to use 200GB and not 400GB. How do I resizing my disk and extend the file system resizing a disk volume?

Thinkpad update firmware on Linux (X1 extreme/P1 gen2)

last updated February 2, 2020 in CentOS, Debian / Ubuntu, Hardware, Linux, RedHat and Friends

I have ThinkPad P1 Gen 2 or X1 Extreme 2nd Laptop. Can I easily Install ThinkPad firmware updates on Linux using GUI?