Along with the many other GUI enhancements that have come with the new version 11 there have been some MAJOR improvements in how spam is handled. While cPanel has always remained an easy to modify system many people do not like to start modifing configuration files. Those people will be happy to learn that now cPanel 11 includes support for RBL support.


To enable it simply login to WHM and click on "Exim Configuration Editor". From here you have your choice of spamhaus and or spamcop, I generally enable both. You can also set lower limits on SpamAssasin in this menu if you would like to be more sensitive. Keep in mind of course as you raise the sensitivity the chances of legit email getting dropped increase.

Overall good job cPanel! This is a feature that has been needed for awhile but is even more important with the recent wave of spam attacks.

I wrote up a quick guide to setting up NFS awhile back but never published it. It is not exactly a nice and clean format but it is exactly what you need to be reading if you want a quick way to setup NFS between two servers. For the purpose of the guide I have added directions for the APF firewall, obviously anything else will work fine.

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The kernel versions are constantly changing so this guide may fall out of date from time to time.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.

There are many different backup solutions that we can deploy for you to ensure they your data is safe. They start at the cheaper options and go up, depending on what level of paranoia you have will determine which you should go with. Each of them has their own advantages and disadvantages. Regardless of the option that you choose it is always advisable to download the site to your local computer occasionally, especially if the site contains very important information. This information was originally for use with Total Server Solutions but it is a good general guide for people thinking about backups.

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.

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.

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.

 

MySQL is one of the most important programs on a server, unfortunatly it is also pretty resource intensive. One a server it is not uncommon for a single user or even a query to take up the bulk of the servers cpu cycles. Mytop is a very useful program to see what queries a server is currently processing as well as which user is executing them. Think of mytop as top for mysql. If you see a lot from a user that means they are probably the hog. Mytop can also be useful for figuring out exactly which queries are causing the problem in the case of a self-designed website. The following is how to install mytop on the server and run it. Thanks to carlos for the actual commands

This guide is here for all those people that are starting a webhosting company but have absolutly no clue how to do it or just how much work it would take to run one. If you are thinking it is still the late 90's and the internet means quick and easy money just close this window now and stop reading...that internet is long gone. The truth of the matter is that there are thousands of webhosting "companies" many of whom are run from the desk of a 13 year old kid, while he is not at school of course. Of course I am not trying to say that all hosts are kiddie hosts, but many are and they are the ones that are willing to sell you a $5/year hosting plan. You have to realize that there are different levels of companies and service, if you try to get in to get the bottom feeder clients that want to pay as litlte as possible you will most likely run into trouble. In this article I will go over some of the things to consider before even trying to run a business.

 

This guide will give an explanation as what ssh keys are and how they can be used on a day to day basis to make a server more secure and logins even faster. Ssh keys very much like the normal lock and key that are found all over. There are two parts to an ssh key, there is the private key and then the public key. The private key is just that, private. If any person is allowed to view or copy that file it becomes possible for them to login to any server that has the public key installed. The public key is just as the name says, public and can be posted anywhere. SSH key authentication works in a two step process. When I connect from a computer with a private key installed the ssh client will offer the private key to the remote server. The remote server then checks the authorized_host2 file which contains a list of all of the public keys that are allowed to authenticate with the server. If there is a match the server will allow the user to login without a plaintext password, the key takes over that function. This process is often faster then putting in a password and saves the trouble of having to write passwords down. A word to the wise, make sure you keep the private key safe!

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

Let me start off my saying that if you are completely unfamiliar with linux when you first get your server be careful with what you do! Unlike windows which has some protections in place to prevent you from completely destroying your computer without realizing it linux does almost nothing to stop you from doing what you want when logged in as root. There are many different single commands that can easily take your server offline in a matter of seconds. I am not trying to scare anybody away from learning, just be careful with what you are doing and respect the power at that being logged in as “root” caries. If you are not familiar with whom the root user is it is the highest administrator account on the server.

This guide is meant to be a simple walkthrough on how to parition a new drive to be used only for backups. If you want to put mysql and a /tmp parition on it check out my other guide located on the left. This guide uses fdisk which is a very powerful tool but you should be fine as long as you are careful in what you do. Use this guide at your own risk! What ever you do make sure to NOT use the command "fdisk /dev/sda" or "fdisk /dev/hda" as that means you are editing your main and boot partition.

 

***WARNING***

***WARNING***

***WARNING***

***WARNING***

***WARNING***

***WARNING***

***WARNING***

 

Be careful and follow this guide precisely :) That all say here is the actual guide.

A recent problem with RHEL and cPanel causes some servers to crash on a daily or every couple of days basis. The normal symptoms of this sort of crashing are having the server crashing at the same time every time that it crashes. If you are having these problems I would suggest that you go ahead and just disable the auditd for now since the system can run fine without it and it seems to be causing a lot of trouble for some people. The below has worked fine for me on hundreds of servers and should not cause any issues.