Download Fedora 11 CD / DVD ISO

Posted on in Categories Download of the day, fedora linux, Gnome, Linux, Linux desktop, Linux distribution, Linux Multimedia, package management, RedHat/Fedora Linux last updated June 10, 2009

Fedora Linux version 11 has been released and available for download ( jump to download link ). Fedora Linux is a community-based Linux distribution. Fedora is sponsored by Red Hat, Inc.

One of Fedora’s main objectives is not only to contain free and open source software, but also to be on the leading edge of such technologies. Fedora 11, codenamed “Leonidas”, was released on June 9, 2009. The features include ext4, a 20-second startup, and the latest GNOME, KDE and XFCE releases. Firefox 3.5 and Thunderbird 3’s latest pre-releases are available as well.

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 June 3, 2009

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.

Linux x86_64: Detecting Hardware Errors

Posted on in Categories CentOS, Debian Linux, fedora linux, Gentoo Linux, Hardware, Howto, kernel, Linux, Linux distribution, Networking, package management, RedHat/Fedora Linux, Shell scripting, Sys admin, Tips, Troubleshooting, Ubuntu Linux last updated June 2, 2009

The Blue Screen of Death (BSoD) is used for the error screen displayed by Microsoft Windows, after encountering a critical system. Linux / UNIX like operating system may get a kernel panic. It is just like BSoD. The BSoD and a kernel panic generated using a Machine Check Exception (MCE). MCE is nothing but feature of AMD / Intel 64 bit systems which is used to detect an unrecoverable hardware problem.

Program such mcelog decodes machine check events (hardware errors) on x86-64 machines running a 64-bit Linux kernel. It should be run regularly as a cron job on any x86-64 Linux system. This is useful for predicting server hardware failure before actual server crash.

ss: Display Linux TCP / UDP Network and Socket Information

Posted on in Categories Debian Linux, Howto, Linux, Monitoring, Networking, RedHat/Fedora Linux, Sys admin, Tips, Troubleshooting, Ubuntu Linux last updated June 2, 2009

The ss command is used to show socket statistics. It can display stats for PACKET sockets, TCP sockets, UDP sockets, DCCP sockets, RAW sockets, Unix domain sockets, and more. It allows showing information similar to netstat command. It can display more TCP and state information than other tools. It is a new, incredibly useful and faster (as compare to netstat) tool for tracking TCP connections and sockets. SS can provide information about:

  • All TCP sockets.
  • All UDP sockets.
  • All established ssh / ftp / http / https connections.
  • All local processes connected to X server.
  • Filtering by state (such as connected, synchronized, SYN-RECV, SYN-SENT,TIME-WAIT), addresses and ports.
  • All the tcp sockets in state FIN-WAIT-1 and much more.

Linux Kernel Security (SELinux vs AppArmor vs Grsecurity)

Posted on in Categories CentOS, Debian Linux, fedora linux, Gentoo Linux, GNU/Open source, Linux, Linux distribution, Networking, RedHat/Fedora Linux, Security, Slackware, Suse Linux, Ubuntu Linux last updated May 27, 2009

Linux kernel is the central component of Linux operating systems. It is responsible for managing the system’s resources, the communication between hardware and software and security. Kernel play a critical role in supporting security at higher levels. Unfortunately, stock kernel is not secured out of box. There are some important Linux kernel patches to secure your box. They differ significantly in how they are administered and how they integrate into the system. They also allow for easy control of access between processes and objects, processes and other processes, and objects and other objects. The following pros and cons list is based upon my personal experience.

Lighttpd mod_rrdtool: Monitor The Load, Requests Per Seconds and Traffic

Posted on in Categories CentOS, Debian Linux, fedora linux, Hardware, Howto, lighttpd, Linux, Monitoring, RedHat/Fedora Linux, Ubuntu Linux last updated May 23, 2009

The round-robin database tool aims to handle time-series data like network bandwidth, temperatures, CPU load etc. The data gets stored in round-robin database so that system storage footprint remains constant over time. Lighttpd comes with mod_rrdtool to monitor the server load and other details. This is useful for debugging and tuning lighttpd / fastcgi server performance.

Red Hat / CentOS VSFTPD FTP Server Configuration

Posted on in Categories CentOS, FTP Server, Howto, Iptables, Linux, RedHat/Fedora Linux, Security, User Management last updated May 21, 2009

Vsftpd (Very Secure FTP Daemon) is an FTP server for UNIX-like systems, including CentOS / RHEL / Fedora and other Linux distributions. It supports IPv6, SSL, locking users to their home directories and many other advanced features.

In this guide you will learn:

  1. Setup vsftpd to provide FTP service.
  2. Configure vsftpd.
  3. Configure Firewalls to protect the FTP server.
  4. Configure vsftpd with SSL/TLS.
  5. Setup vsftpd as download only anonymous internet server.
  6. Setup vsftpd with virtual users and more.

Linux HugeTLBfs: Improve MySQL Database Application Performance

Posted on in Categories CentOS, Hardware, High performance computing, Howto, MySQL, RedHat/Fedora Linux last updated May 20, 2009

Applications that perform a lot of memory accesses (several GBs) may obtain performance improvements by using large pages due to reduced Translation Lookaside Buffer (TLB) misses. HugeTLBfs is memory management feature offered in Linux kernel, which is valuable for applications that use a large virtual address space. It is especially useful for database applications such as MySQL, Oracle and others. Other server software(s) that uses the prefork or similar (e.g. Apache web server) model will also benefit.

The CPU’s Translation Lookaside Buffer (TLB) is a small cache used for storing virtual-to-physical mapping information. By using the TLB, a translation can be performed without referencing the in-memory page table entry that maps the virtual address. However, to keep translations as fast as possible, the TLB is usually small. It is not uncommon for large memory applications to exceed the mapping capacity of the TLB. Users can use the huge page support in Linux kernel by either using the mmap system call or standard SYSv shared memory system calls (shmget, shmat).

How To Use Gmail Account To Relay Email From a Shell Prompt

Posted on in Categories Backup, Debian Linux, fedora linux, Howto, Linux, Linux desktop, RedHat/Fedora Linux, Tip of the day last updated April 5, 2009

Usually, you do not need to setup an email server under Linux desktop operating system. Most GUI email clients (such as Thunderbird) supports Gmail POP3 and IMAP configurations. But, how do you send mail via the standard or /usr/bin/mail user agents or a shell script? Programs such as sendmail / postfix / exim can be configured as a gmail smarthost but they are largely overkill for this use.

Lighttpd Install mod_geoip For Country / City Level Geo Targeting

Posted on in Categories CentOS, Debian Linux, FreeBSD, Gentoo Linux, Howto, lighttpd, Linux, Networking, package management, RedHat/Fedora Linux, Suse Linux, Ubuntu Linux, UNIX last updated March 29, 2009

Geolocation software is used to get the geographic location of visitor using IP address. You can determine country, organization and guess visitors location. This is useful for:

a] Fraud detection.

b] Geo marketing and ad serving.

c] Target content.

d] Spam fighting.

e] And much more.

mod_geoip is a Lighttpd module for fast ip/location lookups. In this tutorial you will learn about mod_geoip installation and php server side examples to determine visitors country.