RHEL Howtos and Guides

Red Hat Enterprise Linux server tutorial for new and advanced users. Topic includes RHEL firewall, package management, Red Hat server security, various server configuration, mail-server, web-server, proxy-server, intrnet-server, file server and much more ( rss feed ).

On 19th March 2015, multiple high and moderate severity level vulnerabilities released in OpenSSL, a Secure Sockets Layer toolkit used in a Linux and Unix-like systems. How can I fix these vulnerabilities on a CentOS/RHEL/Ubuntu and Debian Linux based server? How do I verify that my Linux server has been fixed against the OpenSSL vulnerability?


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?


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?

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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?


The GHOST (CVE-2015-0235) is serious network function vulnerability in Glibc. How do I check and test if a my Linux based server is secure using command line options?


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?


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?