Category: Linux

Linux Server Managment

Define ssh key per host using ansible_ssh_private_key_file nixCraft

I set up SSH keys on a Linux or Unix as per my project needs and cloud hosting providers. I also new to Ansible IT automation and DevOps tool. My management node has keys for Linode, AWS/EC2 and Google cloud....

/ December 1, 2018

Multiple vulnerabilities in FreeBSD NFS server code nixCraft

FreeBSD is a free and open source operating system. The NFS (Network File System) is a server and client application that turn FreeBSD into a file sharing server. Users can upload or update files on a remote NFS server. NFS...

/ November 29, 2018

Linux Find Out What Process Are Using Swap Space nixCraft Updated Tutorials/Posts

The top and free command display the total amount of free and used physical and swap memory in the server. How do I determine which process is using swap space under Linux operating systems? How do I find out swap...

/ November 28, 2018

How to install and configure memcached on Ubuntu Linux 18.04 nixCraft

I would like to reduce the load on my MariaDB/MySQL/PostgreSQL server using memcached. How do I install and configure memcached server on Ubuntu Linux 18.04 LTS?Introduction : Memcached is a high-performance, distributed memory object caching server. It is free and...

/ November 26, 2018

How To Find Out FreeBSD Version and Patch Level Number nixCraft Updated Tutorials/Posts

How do I find out my FreeBSD server version and patch level of the installed system using command line option? Can you tell us command to find out FreeBSD version and kernel patch level?Introduction : You can use any one...

/ November 26, 2018

How To Find My Public IP Address From Command Line On a Linux nixCraft Updated Tutorials/Posts

How do I find out my public IP address on the Linux and OS X Unix command line to use with my own bash shell script without using third party web site? Is there command-line option which will show my...

/ November 25, 2018

How to setup a UFW firewall on Ubuntu 18.04 LTS server nixCraft

How do I setup a firewall with UFW (uncomplicated firewall) on an Ubuntu Linux 18.04 LTS server to restrict traffic on my personal Ubuntu web-server that hosts my cat’s blog? How do I set up a firewall with UFW on...

/ November 25, 2018

Regular Expressions In grep examples nixCraft Updated Tutorials/Posts

How do I use the grep command with regular expressions on a Linux and Unix-like operating systems? How do I use grep and regular expressions to search for text/ words in Linux?Linux comes with GNU grep, which supports extended regular...

/ November 24, 2018

Change Shell To Bash in Linux / Unix nixCraft Updated Tutorials/Posts

How do I switch from a ksh shell to bash on Linux or Unix system? How to change shells on Unix-like system?A shell is nothing but a command that provides a text-only user interface (also known as “command line interface”)...

/ November 23, 2018

How to configure a static IP address on RHEL 8 nixCraft

I am a new sysadmin and RHEL 8 user. My system is configured to use DHCP. How can I switch from DHCP to a static IP address on RHEL 8 system? How do I setup a static TCP/IP address on...

/ November 22, 2018

How do I find out what shell I am using on Linux/Unix? nixCraft Updated Tutorials/Posts

Both Linux and Unix provides various shell out of the box. One can find bash (Bourne Again shell), ksh (Korn shell), csh (C shell)/tcsh (TC shell), sh (Bourne shell) and more installed by default. However, how do you check which...

/ November 19, 2018

Bash foreach loop examples for Linux / Unix nixCraft

I used foreach on a Unix operating system and csh shell loop. Now, I am a Linux operating system. How do I use foreach loop in bash shell running on Linux?The C shell (csh) or the improved version, tcsh is...

/ November 19, 2018

Bash check if process is running or not on Linux / Unix nixCraft

I am new to Linux shell scripting. I am using a CentOS 7 Linux and Ubuntu 18.04 LTS server in the cloud. How do I check if a process is running or not on Linux? How do I determine whether...

/ November 18, 2018

How to create VM using the qcow2 image file in KVM nixCraft

I have image.qcow2 file. How do I install the qcow2 image provided in the qcow2 format? How do I create Linux KVM VM from provided image (say image.qcow2) file?Introduction: qcow is nothing but a disk file format used by QEMU....

/ November 18, 2018