≡ Menu

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 ).

KVM libvirt assign static guest IP addresses using DHCP on the virtual machine

I am using KVM/libvirt on Linux operating system and how do I assign static IP address using dnsmasq dhcpd server for my default virtual network switch?
[click to continue…]

How to copy permissions from one file to another on Linux

I need to copy or clone file ownership and permissions from another file on Linux. Is there a bash command line option to clone the user, group ownership and permissions on a file from another file on Linux operating system?
[click to continue…]

A stack-based critical buffer overflow was found in the way the libresolv library (glibc) performed dual A/AAAA DNS queries. A remote attacker could crash or, potentially, execute code running the library on Linux. How do I patch and protect my server or workstation against the glibc getaddrinfo on Linux operating system?
[click to continue…]

Linux Check Disk Space Command

I recently switched from a Windows server to a Linux server operating system. I am using Ubuntu LTS server. How do I find out disk space utilization information using command line option?
[click to continue…]

How To Patch and Protect Linux Kernel Zero Day Vulnerability CVE-2016-0728 [ 19/Jan/2016 ]

A very serious security problem has been found in the Linux kernel. A 0-day local privilege escalation vulnerability has existed since 2012. This bug affects millions of Android or Linux applications to escalate privileges. Any server or desktop (32 or 64 bit) with Linux Kernel version 3.8+ is vulnerable. How do I fix this problem?
[click to continue…]

The OpenSSH project released an ssh client bug info that can leak private keys to malicious servers. A man-in-the-middle kind of attack identified and fixed in OpenSSH are dubbed CVE-2016-0777 and CVE-2016-0778. How do I fix OpenSSH’s client vulnerability on a Linux or Unix-like operating system?
[click to continue…]

How to list all iptables rules with line numbers on Linux

I recently added NAT rules on my RHEL 6.x system. How do I see the rules including line numbers that I just added in Linux?
[click to continue…]

How to check boot path (partition) in Linux

How do I identify the boot device or boot path in Linux operating system?
[click to continue…]

How to delete a single command from history on a Linux, OS X and Unix Bash shell

I‘m working in Ubuntu bash terminal application and remotely on a RHEL server in cloud platform. I typed the wrong and dangerous command. I no longer wish to remember dangerous command in the history file. How can I remove or delete a single command from bash history file?
[click to continue…]

How to backup and restore a partition table on Linux

Is it possible to just backup my Linux partition table and restore it when required? How do I restore partition table if it get deleted by mistake on Linux operating system? How do I backup and restore a GPT partition table on Linux?
[click to continue…]