Linux / Unix Desktop Fun: Text Mode ASCII-art Box and Comment Drawing

Posted on in Categories Linux, Linux desktop last updated June 11, 2012

Boxes command is a text filter and a little known tool that can draw any kind of ASCII art box around its input text or code for fun and profit. You can quickly create email signatures, or create regional comments in any programming language. This command was intended to be used with the vim text editor, but can be tied to any text editor which supports filters, as well as from the command line as a standalone tool.

Linux debugfs Hack: Undelete Files

Posted on in Categories Linux last updated May 3, 2012

Undeletion means restoring files which have been deleted from Linux ext3 file system using rm command. Deleted files can be recovered on ext3 file systems using the debugfs program. This quick tutorial describes how to recover a file that was recently deleted using nothing but standard Linux command line utilities.

How To: Upgrade Red Hat Enterprise Linux 5.3 to v5.4

Posted on in Categories GNU/Open source, Hardware, Howto, Linux, Linux distribution, News, package management, RedHat/Fedora Linux last updated September 2, 2009

Red Hat Enterprise Linux v5.4 has been released and available via RHN for immediate update. The new version includes the kernel-based virtual machine (KVM) virtualization, next generation of developer features and tools including GCC 4.4, a new malloc(). Also included clustered, high-availability filesystem to support Microsoft Windows storage needs on Red Hat Enterprise Linux.

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.

Red Hat / CentOS Apache 2 FastCGI PHP Configuration

Posted on in Categories Apache, CentOS, Howto, Networking, package management, php, RedHat/Fedora Linux, Security, Tips last updated December 30, 2008

FastCGI is a protocol for interfacing interactive programs with a web server. FastCGI’s main aim is to reduce the overhead associated with interfacing the web server and CGI programs, allowing a server to handle more web page requests at once.

Also, PHP is not recommended with multithreaded Apache2 (worker MPM) because of performance and some 3rd party PHP extensions are not not guaranteed thread-safe.

nginx and lighttpd has inbuilt support for FastCGI. For Apache web server you need to use either mod_fastcgi or mod_fcgid.

mod_fastcgi allows server and application processes to be restarted independently — an important consideration for busy web sites. It also facilitates per-application security policies — important for ISPs and web hosting companies.

In this quick tutorial, you will learn about Apache 2 + mod_fastcgi + PHP installation and configuration under Red Hat Enterprise Linux / CentOS Linux version 5.x+.

Red Hat / CentOS Linux 5.x: Perl Performance Bug Fix Available

Posted on in Categories CentOS, GNU/Open source, High performance computing, Linux, Linux distribution, package management, RedHat/Fedora Linux last updated September 21, 2008

Perl version supplied with RHEL has bug, which will result code running at least 100 times slower than expected speed. Now, Red Hat updated perl packages that fix a performance issue. Earlier only solution was installing your own perl under /usr/local or other location. This fix will now take care of performance penalty.

CentOS / Red Hat Enterprise Linux 5.2 Poor NFS Performance and Solution

Posted on in Categories Apache, CentOS, data center, File system, High performance computing, Howto, Linux, Linux distribution, Networking, package management, RedHat/Fedora Linux, Security Alert, Storage, Sys admin, Troubleshooting, Tuning last updated August 22, 2008

A few days ago I noticed that NFS performance between a web server node and NFS server went down by 50%. NFS was optimized and the only thing was updated Red Hat kernel v5.2. I also noticed same trend on CentOS 5.2 64 bit edition.