The business world is already filling up with cloud computing offerings for productivity (email, calendar systems, etc – think Google), and advanced remote storage (think Amazon), but IBM is tapping into an apparent opening for cloud-based software development. Developers will be able to develop and test applications in the cloud.

Red Hat, famous for its early hugely popular Redhat Linux, continues to make strides in the enterprise market with its Redhat Enterprise Linux and now with its virtualization technology. IBM does not anticipate an overnight success but intends to build a substantial increase over time. Although cloud computing enters the news frequently, it still only counts for a fraction of all web hosting with many businesses still preferring locally hosted solutions.

Source: ServerWatch

Note: It is recommended that you use an ext2 or ext3 file system if you want per-container disk quota.

1. Add the OpenVZ YUM repository:

# cd /etc/yum.repos.d
# wget http://download.openvz.org/openvz.repo
# rpm --import http://download.openvz.org/RPM-GPG-Key-OpenVZ

2. Find out which kernel version you need and install it:

# yum install ovzkernel[-flavor]

3. Change the new GRUB bootloader lines created when you installed the kernel to look something like this in /boot/grub/grub.conf:

title OpenVZ (2.6.8-022stab029.1)
root (hd0,0)
kernel /vmlinuz-2.6.8-022stab029.1 ro root=/dev/sda5
initrd /initrd-2.6.8-022stab029.1.img

That’s it! You now have OpenVZ installed. Visit the OpenVZ wiki for more information about configuring your new installation.

Source: OpenVZ Quick Installation

1. Install the EPEL repository:

# rpm -Uvh http://download.fedora.redhat.com/pub/epel/5Server/x86_64/epel-release-5-3.noarch.rpm

2. Install nginx

# yum install nginx

3. You will be asked to install the gpg-key for EPEL. Answer yes

4. Start Nginx

# /etc/init.d/nginx start

5. Check the installation by going to your web server’s default site, either using your ip address or domain name.

Answer: There exists a Linux tool for just about everything, and this is no exception. You need a tool called fdupes, which searches the path you give it for duplicate files and uses several comparison techniques (sizes, MD5 signatures, byte-by-byte comparison) to find and eliminate duplicates.

First install fdupes. In RHEL/Fedora/CentOS, use the rpmforge repository enter:

# yum install fdupes

To find duplicates in the /etc directory, you would enter:

# fdupes /etc

To force fdupes to prompt you whether to preserve or delete files:

#fdupes -d /etc

As you can see, fdupes might be just what you need to clean up your server and possibly increase that precious disk space.

Source: nixCraft
Photo: Wikimedia Commons

Redhat Enterprise Linux – With the biggest financial revenue in the Linux market, Redhat is a force to be reckoned with, but whether they are right for your web hosting company depends on how much you can afford. If you like Redhat, you might consider CentOS.

CentOS – A free alternative to RHEL, based on the same source code, minus Redhat’s guarantees, technical support, and logo artwork.

Fedora – The cutting-edge testbed for RHEL. This is a community driven OS with a lot of community support but not paid technical support.

Debian – A community-based distribution known for its stability and large software repository, Debian might be perfect for a server that might not need the latest apps but needs to work consistently.

Ubuntu Server Edition – Although it is famous for its desktop Linux offerings, Ubuntu, a Debian-based OS, is a force to be reckoned with.

SUSE Linux Enterprise – Novell’s direct competition with RHEL, this OS is backed by Novell’s long history of server support and also some deals with Microsoft that have brought a degree of controversy.

Slackware – Described by “distrowatch” as “highly technical” and “clean”, Slackware sticks to the principles that made UNIX rock solid for decades but comes in a nice free Linux package. You need to know your stuff to use Slackware, and don’t expect a lot of glamour.

Gentoo – One of the newer major players on the block, Gentoo is a complete rethinking of the way a Linux distribution should be handled, largely build around the FreeBSD “ports” feature, which builds packages from source automatically. It is highly customizable but can be time consuming and unstable for those who are not experienced with it.

Photo: Flickr

Answer: Most Linux distributions come with more than what you need. They are designed to not only work on servers but also desktop computers, laptops, netbooks, and in some cases, even smaller mobile devices like phones. Because of this there are sometimes numerous services running that you may not need. Similarly, there might be special server-oriented services that you will want to enable.

Security is also an issue. In the past we covered X.org and why it is a bad idea to have it running on a server. There are other services like X.org that might be good for the desktop but are superfluous on a server. The first thing to do is to find out which services are currently running. Execute the following commands:

#service --status-all
#chkconfig --list | grep '3:on'

You can read the rest of the steps in tis process at nixCraft. Everything in the complete how-to article will cover CentOS, Fedora, and Redhat Enterprise Linux.

Source: nixCraft

Answer: Yes, there certainly is, and there is a good reason to do so. While the version of Apache running on your server might be inconsequential to the average, it could be ammunition in the sneaky minds of would-be hackers. If they know which version of Apache you are running, they also know what vulnerabilities you have.

Ideally, you will always have the latest, most secure version, but security holes pop up and spread very quickly in the Internet underground, sometimes even before developers and security watchdogs can find them.

To hide your Apache version from all visitors, simply add two directive to your, Apache configuration file. On Redhat-based systems, you need to edit httpd.conf, which is found in the /etc/httpd directory. Find these two lines or add them:

ServerTokens ProductOnly
ServerSignature Off

That is all it takes. Now outside users will not be able to see what version of Apache server you are running no matter what software they have.

For example, the httpd file under sysconfig is the configuration for the httpd server rather than Apache as a whole. In it you can set startup options and command flags. Other configuration files include crond (for configuring the crontab frequency), syslog (which configures the system log rotation), and spamassassin (setup for the spam filtering service).

One of the most important folders in sysconfig is “networking“. This is where a user sets up network devices, and devices that are automatically setup appear here as well. You would only need to configure this file if you were running a locally housed server. If your server is remote, this will never need to be changed and attempting to change it could cause you to lose the ability to access the server at all. I recommend browsing through the complete list of files in /etc/sysconfig and at least becoming aware of them, in case you need one of them in the future.

Answer: Early version of YUM did not have a “reinstall” function, but the newest version do. To reinstall a package, simply type as root:

yum reinstall package-name

If you are running a server with an older version of Fedora or other Redhat-based Linux distribution, your version of YUM may not support reinstallation. In such a case, you will have to manually reinstall it. From root, enter a command such as this to remove the files from the database:

rpm -e --justdb --nodeps packagename

YUM will then believe the package is not installed, even though it still is. Install as you normally would with:

yum install package-name

To install APT, follow these simple steps:

Download the corresponding Redhat Enterprise Linux package from this repository. Install it with:

rpm -Uhv package-name-release.rpm

Now to install APT, use YUM:

yum install apt

Now, you should be able to use APT to install and update Redhat, Fedora or CentOS packages. Tomorrow, you will learn how to use APT and some common tricks.