Tips To Protect Linux Servers Physical Console Access

Posted on in Categories Debian Linux, Hardware, Howto, Kde, Linux, Linux desktop, Linux distribution, package management, RedHat/Fedora Linux, Sys admin, Tips, Ubuntu Linux last updated March 12, 2009

This is an user contributed article.

Linux computer console is a physical device to operate a computer / server. Here are few steps which, if taken, make it more difficult for an attacker to quickly modify a system from its console.

Linux Convert ext3 to ext4 File system

Posted on in Categories CentOS, Data recovery, Linux, Linux desktop, Linux distribution, RedHat/Fedora Linux, Storage, Suse Linux, Sys admin, Tips, Troubleshooting, Tuning, Ubuntu Linux last updated January 23, 2009

Some time ago ext4 was released and available for Linux kernel. ext4 provides some additional benefits and perforce over ext3 file system. You can easily convert ext3 to ext4 file system. The next release of Fedora, 11, will default to the ext4 file system unless serious regressions are seen. In this quick tutorial you will learn about converting ext3 to ext4 file system.

Tutorial: OpenOffice.Org Mail Merge

Posted on in Categories fedora linux, Gnome, GNU/Open source, Howto, Linux, Linux desktop, OS X, Tips, Ubuntu Linux, UNIX, Windows last updated January 14, 2009

openoffice

Mail merge is a software function describing the production of multiple documents from a single template form and a structured data source. This helps to create personalized letters and pre-addressed envelopes or mailing labels for mass mailings from a word processing document which contains fixed text, which will be the same in each output document, and variables, which act as placeholders that are replaced by text from the data source. The data source is typically a spreadsheet or a database which has a field or column matching each variable in the template. When the mail merge is run, the word processing system creates an output document for each row in the database, using the fixed text exactly as it appears in the template, but substituting the data variables in the template with the values from the matching columns.

This technique of merging data to create mailshots gave rise to the term mail merge. OpenOffice.Org has a in built software mail merge feature.

If you haven’t tried OpenOffice.org’s mail merge feature because you find it confusing or difficult to use, you are in luck. Mail Merges in OpenOffice.org and StarOffice provides a detailed description of the mail merge feature from start to finish. Among other things, it shows how you can use the mail merge to create letters, labels, and envelopes.

=> You can download this excellent PDF ebook for your persusal or read the article online – Mail Merge in Openoffice.org: Everything You Need to Know.

FreeBSD Turn On Process Accounting – Track System Resources Used By Users

Posted on in Categories FreeBSD, Howto, Monitoring, Security, Sys admin, Tips, Troubleshooting, Tuning last updated January 8, 2009

I’ve already written about Linux process accounting under Linux ( see how to keep a detailed audit trail of what’s being done on your Linux systems). You can easily setup process accounting under FreeBSD. This tutorial expalins how to enable and utilizing FreeBSD process accounting including many other useful options are explained to keep track of system resources used, and their allocation among users.

Leap Second To Be Added End Of 2008 And Its Impact On Clustered Computers / Network

Posted on in Categories Hardware, High performance computing, Linux, News, Sys admin, Tips, UNIX, Windows server last updated December 31, 2008

Get ready for a minute with 61 seconds. Scientists are delaying the start of 2009 by the first ‘leap second’ a timing tweak meant to make up for changes in the Earth’s rotation.

The aged Earth is slowing down in its daily rotation, at least in the current epoch. So a leap second is added (a one-second adjustment added) to our time. This year will be exactly one second longer.

Precise time measurements are needed for high-speed communications systems among other modern technologies such as clusters, GPS, networks. You need to make sure that you are running updated version of ntpd that support leap second for UNIX and Windows computers.

Apache2 mod_fastcgi: Connect to External PHP via UNIX Socket or TCP/IP Port

Posted on in Categories Apache, CentOS, fedora linux, Howto, lighttpd, Networking, php, RedHat/Fedora Linux, Security, Tips, Troubleshooting, Tuning last updated December 30, 2008

Now, mod_fastcgi is configured and running. FastCGI supports connection via UNIX sockets or TCP/IP networking. This is useful to spread load among various backends. For example, php will be severed from 192.168.1.10 and python / ruby on rails will be severed from 192.168.1.11. This is only possible with mod_fastcgi.

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+.

How To Convert From a VMware Image To Virtualbox Image

Posted on in Categories GNU/Open source, Hardware, Howto, Linux, Linux desktop, Linux distribution, Linux Virtualization, package management, Tips, vmware, Windows, windows vista last updated December 22, 2008

VirtualBox is a virtual emulator like VMWare workstation. It has many of the features VMWare has, as well as some of its own.

I really like new Opensource VirtualBox from Sun. It is light on resources. Here is a quick tip – you can convert a VMware virtual machine (image) to a VirtualBox machine (image) using qemu-img utility, without reinstalling the GUEST operating system