Download CentOS 6.1 CD / DVD ISO

Posted on in Categories CentOS, Download of the day last updated December 12, 2011

CentOS Linux version 6.1 has been released and available for the download. It is a community-supported operating system based on Red Hat Enterprise Linux (RHEL) version 6.1. CentOS Linux is considered as the most popular Linux distribution for web servers and general purposes usage.

Download CentOS 6 CD / DVD ISO

Posted on in Categories CentOS, Download of the day last updated July 11, 2011

CentOS Linux version 6 has been released. It is a community-supported operating system based on Red Hat Enterprise Linux (RHEL) version 6. CentOS Linux is considered as the most popular Linux distribution for web servers with almost 30% of all Linux servers using it.

CentOS Linux Project In Trouble

Posted on in Categories CentOS, GNU/Open source, Linux, Linux distribution, RedHat/Fedora Linux last updated July 30, 2009

CentOS is a community-supported, freely-available operating system based on Red Hat Enterprise Linux. Lance Davis created CentOS and now he goes absent without leave. In an open letter from his fellow CentOS developers:

You have long promised a statement of CentOS project funds; to this date this has not appeared. You hold sole control of the centos.org domain with no deputy; this is not proper. You have, it seems, sole ‘Founders’ rights in the IRC channels with no deputy ; this is not proper.

BIND 9 Dynamic Update DoS Security Update

Posted on in Categories BIND Dns, CentOS, Debian Linux, fedora linux, FreeBSD, Howto, Linux, Networking, package management, RedHat/Fedora Linux, Security, Solaris, Suse Linux, Sys admin, UNIX, Windows server last updated July 29, 2009

BIND 9 is an implementation of the Domain Name System (DNS) protocols. named daemon is an Internet Domain Name Server for UNIX like operating systems. Dynamic update messages may be used to update records in a master zone on a nameserver. When named receives a specially crafted dynamic update message an internal assertion check is triggered which causes named to exit. An attacker which can send DNS requests to a nameserver can cause it to exit, thus creating a Denial of Service situation. configuring named to ignore dynamic updates is NOT sufficient to protect it from this vulnerability. This exploit is public. Please upgrade immediately.

Top 20 OpenSSH Server Best Security Practices

Posted on in Categories CentOS, Debian Linux, fedora linux, FreeBSD, Gentoo Linux, Howto, Linux, Networking, package management, RedHat/Fedora Linux, Security, Suse Linux, Sys admin, Tips, Ubuntu Linux, UNIX last updated July 24, 2009
Don't tell anyone that I'm free

OpenSSH is the implementation of the SSH protocol. OpenSSH is recommended for remote login, making backups, remote file transfer via scp or sftp, and much more. SSH is perfect to keep confidentiality and integrity for data exchanged between two networks and systems. However, the main advantage is server authentication, through the use of public key cryptography. From time to time there are rumors about OpenSSH zero day exploit. Here are a few things you need to tweak in order to improve OpenSSH server security.

Vmware Linux Guest Add a New Hard Disk Without Rebooting Guest

Posted on in Categories CentOS, fedora linux, Hardware, Howto, Linux, Linux desktop, Linux distribution, Linux Virtualization, RedHat/Fedora Linux, Storage, Sys admin, Tips, vmware last updated July 18, 2009

As a system admin, I need to use additional hard drives for to provide more storage space or to separate system data from user data. This procedure, adding physical block devices to virtualized guests, describes how to add a hard drive on the host to a virtualized guest using VMWare software running Linux as guest.

It is possible to add or remove a SCSI device explicitly, or to re-scan an entire SCSI bus without rebooting a running Linux VM guest. This how to is tested under Vmware Server and Vmware Workstation v6.0 (but should work with older version too). All instructions are tested on RHEL, Fedora, CentOS and Ubuntu Linux guest / hosts operating systems.

20 Linux System Monitoring Tools Every SysAdmin Should Know

Posted on in Categories CentOS, Debian Linux, Howto, Linux, Monitoring, Networking, RedHat/Fedora Linux, Security, Sys admin last updated June 27, 2009

Need to monitor Linux server performance? Try these built-in commands and a few add-on tools. Most Linux distributions are equipped with tons of monitoring. These tools provide metrics which can be used to get information about system activities. You can use these tools to find the possible causes of a performance problem. The commands discussed below are some of the most basic commands when it comes to system analysis and debugging server issues such as:

  1. Finding out bottlenecks.
  2. Disk (storage) bottlenecks.
  3. CPU and memory bottlenecks.
  4. Network bottlenecks.

Lighttpd Traffic Shaping: Throttle Connections Per Single IP (Rate Limit)

Posted on in Categories Apache, CentOS, fedora linux, FreeBSD, Howto, Iptables, lighttpd, Linux, Networking, PF Firewall, RedHat/Fedora Linux, Security, Ubuntu Linux, UNIX last updated June 21, 2009

If you do not control or throttle end users, your server may run out of resources. Spammers, abuser and badly written bots can eat up all your bandwidth. A webserver must keep an eye on connections and limit connections per second. This is serving 101. The default is no limit. Lighttpd can limit the throughput for each single connection (per IP) or for all connections. You also need to a use firewall to limit connections per second. In this article I will cover firewall and lighttpd web server settings to throttle end users. The firewall settings can be applied to other web servers such as Apache / Nginx and IIS server behind PF / netfilter based firewall.

Linux Find Out If PCI Hardware Supported or Not In The Current Running Kernel

Posted on in Categories CentOS, Debian Linux, fedora linux, Gentoo Linux, GNU/Open source, Hardware, Howto, Linux, RedHat/Fedora Linux, Sys admin, Tips last updated August 1, 2017

From my mailbag:

How do I find out if a given PCI hardware is supported of by the current CentOS / Debian / RHEL / Fedora Linux kernel?

You can easily find out find out if a given piece of PCI hardware such as RAID, network, sound, graphics card is supported or not by the current Linux kernel using the following utilities under any Linux distributions.