Missing Memory

Posted on in Categories Howto, Linux, RedHat/Fedora Linux, Sys admin, Troubleshooting, UNIX, Windows server last updated April 22, 2009

Today, I’ve upgraded total 8 servers from 4GiB to 8GiB to improve performance of system by inserting additional memory modules. We started each server and checked for memory count at console. All severs booted normally after the upgrade and services such as SMTP, NFS, CIFS, HTTP started as expected. Shortly, afterwords I got a call from help desk about pop3 server for slow performance.

Howto Upgrade Debian 4 Etch to Debian 5.0 Lenny

Posted on in Categories Debian Linux, GNU/Open source, Howto, Linux, Linux desktop, Linux distribution, Security, Troubleshooting last updated February 16, 2009

Debian version 5.0 has been released. It is recommended that you upgrade the system to latest version. Upgrading remote Debian server is a piece of cake. In this tutorial, you will learn about upgrading Debian Linux server from Etch to Lenny over ssh session.

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 24, 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.

BIND Named: Set a Zone Transfer IP Address For Master DNS Server

Posted on in Categories BIND Dns, CentOS, data center, fedora linux, FreeBSD, High performance computing, Linux Scalability, RedHat/Fedora Linux, Troubleshooting last updated January 8, 2009

I’ve three nameserver load-balanced (LB) in three geo locations. Each LB has a front end public IP address and two backend IP address (one for BIND and another for zone transfer) are assigned to actual bind 9 server running Linux. So when a zone transfer initiates from slave server, all I get errors. A connection cannot be established, it tries again with the servers main ip or LB2 / LB3 ip. This is a problem because my servers are geo located and load balanced. However, there is a small workaround for this problem.

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.

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.