DNS recursive
For who have recently notice that now DNSreport do verify if your DNS is recursive lookup or not, here is the tip on how to set it up.
open you named.conf and add before options { the follow lines:
acl “trusted” {
xxx.xxx.xxx.xxx;
yyy.yyy.yyy.yyy;
};
RPM Kernel Upgrade
This is a very simple guide meant for people unfamiliar with upgrading kernels on a linux system. It is fairly simple to follow and I have done this on many servers so if you take your time and read though it you should have no problem. I take no responsibility if something goes wrong on your server because of this! This guide is formated for a RHEL server but if you understand the concept it can be applied to any rpm kernel.
Updated August with new versions
The kernel versions are constantly changing so this guide may fall out of date from time to time. The important thing to remember is when you are doing the up2date –download simply look at the version that is downloaded. That is going to be the latest version and in turn the version you want to install and boot to. RHEL or CentOS 5 follow the same basic method.
A linux primer
This guide is meant to provide information to those that may still be teething on linux and are not yet familiar with the differences it has with other operating systems. I am also going to cover some of the basic things that should be done about security and the often overlooked importance of backups. Since most of my articles are targeted at people within the hosting industry I am going to write the guide slanted more towards that group. If you have any more ideas or suggestions as to what I should add to this article please give me some suggestions! I am going to gradually try to add some more information, like in the area of how to use ssh.
*Updated August 8th* Fixed some typo’s and added a little bit more (more…)
Increasing TCP IP Efficiency
Okay, Well… This script is not a security script, nore a load balencing script. But it is a very useful script if you get high traffic or are hosting a Game Server. I’ve Had CounterStrike Server player ping go down as much as 50ms after running this script.
So what you want to do is log into your server’s shell, and create a file (nano filename.sh). Once you create the file, you need to put this code in the file;
Installing zend optimizer
cPanel’s /scripts/installzendopt generally works if you run the cPanel control panel. If you do not the Zend website has an installer which is basically the same thing and works great. If you do not want to search the site I have provided a mirror of the files below. If you do please use version http://eth0.us/files/ZendOptimizer-3.2.8-linux-glibc21-i386.tar.gzas it is compatible with php5 and php4
Updated August 2007
Zend optimizer is a plugin to php which allows a server to read zend encoded files as well as serve as a platform to install zend modules such as eaccelerator.
I have a local copy of the files:
cd /usr/local/src
wget http://eth0.us/files/ZendOptimizer-3.2.8-linux-glibc21-i386.tar.gz
tar -zxf 3.2.8-linux-glibc21-i386.tar.gz
cd 3.2.8-linux-glibc21-i386
./install
Now just hit enter a few times until it is done and you are done! It is as easy as that.
Add an ip address
This is a quick guide on adding IPs to a system manually. I would only suggest it if you are not using a control panel, such as cpanel, that has a feature to adds ips. If your main ethernet device is eth1 instead of eth0 simply substitute eth1 for eth0. Other then that should be pretty simple to follow, this should work on any standard redhat/centos based system.
Login as root then do the following to add a new ip address to any linux redhat based system. If you have cpanel there is a nice little ip management script that just lets you do it via WHM. For those without cpanel do the following:
cd /etc/sysconfig/network-scripts
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Change the mysql directory
While not all datacenters do there are some that by default partition the system in a less then ideal manner. I have had to deal with quiet a few clients who have filled up their /var partition due to mysql being stored by default on the partition. This is a short little guide to show you how to move mysql to another parition on the system. I have another guide that shows you how to parition a drive for mysql but many times it is not possible to repartition a drive and it is a lot easier to simply move it to another live parition. I would make sure and leave mysql in the old place, or at least a backup copy, for a few days before deleting it to make sure all of the data was transfered fine. If you want to move to a partition other then /backup/ simply change backup to home or the partition name anyplace you see it. In addition to the space considerations moving to a different drive can also have a profound positive influence on the system performance.
First edit the my.cnf:
Install subversion version management system (cvs replacement)
Subversion is a program much like cvs that allows for version management. Though I am not extremely familiar with it I was asked to install it on a redhat enterprise 3 update 6 server. The following rpms should work great as long as you have it running the latest according to up2date. If you have RHEL4 you can apparently just do up2date -l subversion. Anyways simply download and install these rpms:
Compile php 4.4.1 from source
cd /usr/local/src/
wget http://ve.php.net/get/php-4.4.1.tar.gz/from/us2.php.net/mirror
tar -zxf php-4.4.1.tar.gz
cd php-4.4.1
up2date libpng-devel libjpeg-devel freetype-devel freetype libjpeg libpng
ln -s /usr/lib/libjpeg.so.62 /usr/lib/libjpeg.so
ln -s /usr/lib/libpng.so.3.1.2.2 /usr/lib/libpng.so
Optimizing host.conf and sysctl.conf
Well, here is another net-based optimization script i have for you. It also is not a masterpiece, but when you include this with everything else, this small addition is the topping to the cake.
#!/bin/sh
cp /etc/host.conf /etc/host.back
echo “# Lookup names via DNS first then fall back to /etc/hosts.” > /etc/host.conf
echo “order bind,hosts” >> /etc/host.conf
echo “# We have machines with multiple IP addresses.” >> /etc/host.conf
echo “multi on” >> /etc/host.conf