≡ Menu

CentOS Howtos and Tutorials

Centos Linux tutorial for beginners and advanced users with special focus on security, firewall, web, mail, file and proxy servers in an enterprise environment (rss feed).

I'm using RHEL 7.1-4 container on a RHEL /CentOS Linux 7.x server. However, I'm unable to ping external site/IP address using the ping command. I'm getting the following error on screen:

ping: Operation not permitted

How do I fix this problem?
[click to continue…]

How can I mount remote directory with ssh on a Linux bases system? How do I use SSHFS to mount remote file systems over SSH on a Ubuntu or Debian/RHEL/CentOS/Arch Linux system?
[click to continue…]

How can I modify partition labels on a Linux operating systems? How to change disk name on the ext4 file system on a Ubuntu Linux using command line?
[click to continue…]

There are certain files in Ubuntu Linux (or Unix-like systems) that only root user access or edit. How can I edit and/or open files that requires admin (root) access on a Ubuntu Linux?
[click to continue…]

I'm a new Ubuntu Linux user. In Linux, Apple OS X or Unix-like systems, how do I reissue or repeat a long command without retying it?
[click to continue…]

A very serious security problem has been found in the GNU C Library (Glibc) called GHOST. How can I fix GHOST vulnerability and protect my Linux server against the attack? How do I verify that my server has been fixed against the Glibc GHOST vulnerability?
[click to continue…]

How To Change Timezone on a CentOS 6 and 7

I set my time zone to 'America/New_York' on a CentOS Linux 7 server. I want to see date and time in my timezone in log files. How can I change the current timezone from 'America/New_York' to 'America/Chicago' using command line?
[click to continue…]