Migration from One OS to Another

Migrating a server is never really a good idea, but in some cases, it may be just what you need for business growth or website stability and security. Depending on your needs, you may be switch from Windows to Linux, Linux to Windows, Solaris to BSD, or any number of possibilities. When you do switch, there are a few issues you should consider.

1. Find out what is compatible and what will not convert over to the new system. HTML files and other static material will. But will scripts written in PHP, ASP, Perl, etc. be lost?

2. Test any data conversion before pulling the plug on the old server. Just because your old Solaris server ran MySQL does not mean that your data will work without any glitches on the new Linux server with MySQL. They may be different versions or have different settings enabled. Test and retest.

3. Try out the new server and learn its administrative ins and outs. Do not wait until you have a security problem to realize you have no idea what to do.

4. Consider the financial ramifications. While moving from licensed software to free software is probably a good step in the long run, you still might have expenses. Make sure you take those into account.

5. Finally, make sure you have backups of everything and a backup plan if it all falls apart. Good luck!

Photo Source: Flickr

Linux vs. Other Free Unices

Linux is undoubtedly the most popular Unix-like operating system, and it is increasingly becoming the number-one choice for web servers, virtualization, and cloud computing. But it is not the only Unix-like OS on the map, and there are a few that rival Linux in terms of stability, security, and ease of use.

Among the most likely candidates to compete with Linux for the title of “Server King” are Solaris and BSD. Solaris was originally produced by Sun Microsystems, which has since been acquired by Oracle. One might consider the future of this OS as uncertain, but a free and open source version, OpenSolaris, ensures that the community can keep it alive even if Oracle does not.

BSD, originally created at the University of California in Berkeley is the primary Linux competitor in the server market, with several variants of its own that are similar to the Linux distribution model. Some of the more common include FreeBSD, NetBSD, and OpenBSD. OpenBSD in particular is known for its security-oriented development, and the creators of it are also responsible for OpenSSH, the secure shell server and client. In the coming weeks, we will look at both of these operating systems and see how they stack up against Linux.

Photo Source: Flickr

Open source vs proprietary servers

Open Source typically refers to software that has code released under some type of free software license (GPL, BSD, Apache, etc.). Users and developers have access to the source code and can modify and redistribute it. Proprietary software usually means the source code is closed and/or the EULA (end user license agreement) forbids redistribution, copying, etc.

The benefit of open source software is that there is a large community involved in supporting it, finding bugs, and making it secure. For a server, this means that your software is not going anywhere even if the hardware vendor goes out of business. With proprietary software, you are at the mercy of the vendor or software developer when you need something fixed or have security problems.

The benefit of proprietary software is usually only evident if you make web applications in-house and do not intend to release that software to the outside public. In such cases you may view the software as your intellectual property. The cost for maintaining each varies depending on the setup and who you have maintaining it. If you or your employees have the knowledge to maintain free software, you can save a considerable amount of money.

Web server round-up

Over the past year, we have discussed several web servers. For your convenience, here is a quick list of each one we have already mentioned, as well as a couple we did not, including links to their project sites.

Apache – This is the most widely used and the one we have spent the most time covering. It is free and open source and runs on nearly every platform available. It is released under the Apache license.

Microsoft IIS – As Microsoft’s proprietary web server, it only comes with and works on Windows. If for some reason you have to run this but do not have Windows, you will have to consider virtualization.

Sun Java System Web Server – This is Sun’s proprietary web server technology that is primarily intended for Sun appliances. Nevertheless, it is cross-platform, and Sun recently opened some of its code under a BSD license.

Ngnix – This is a lightweight web server that runs on both Unix and Windows machines. It has become the fourth most popular HTTP server and is available under a BSD-style license.

Lighttpd – This lightweight HTTP server is designed to take on heavy loads while maintaining a good balance, low memory and CPU usage. It powers YouTube, Wikipedia, and many other high-traffic sites. It is free and open source under a BSD style license.

Photo: Flickr

Using virtualization to host multiple operating systems

This week we have learned about several different server-ready operating systems. But what should you do if you need to run multiple operating systems? Should you fork out the cash for multiple servers? It really depends on your needs, but if you know you will not need an entire dedicated server for each OS, you can save money with virtualization.

Common proprietary virtualization solutions include VMWare and Microsoft’s Hyper-V. Open source solutions include Xen, VirtualBox, and OpenVZ. What virtualization allows you to do is run “virtual machines” within your main (host) operating system. For example, you might have a Linux server, but through virtualization, you can also run Windows and BSD on the same box.

Virtual machines can be customized to use specified amounts of resources. This ensures that you do not over tax your server. Furthermore, some operating systems might require more RAM, for example, than others. While the backend administration will make the virtualization obvious, users who login to the virtual machines will have no idea that they are working in a virtual environment.

Photo: Flickr

BSD and its descendants

In a previous post, we looked at FreeBSD, one of the descendants of the Berkeley Software Distribution (BSD), which was a Unix-like operating system developed at the University of California at Berkeley. There are other descendants of BSD that have developed as well. Here is a quick overview of them:

FreeBSD, which is the most popular, includes its own descendants, such as DragonFlyBSD, PC-BSD (designed specifically for the desktop), and Apple’s Darwin, which is the core of Mac OS X.

NetBSD focuses on portability, stability, and clean design.

OpenBSD is a fork of NetBSD and is very popular for its security features. Many derivative security projects, such as OpenSSH, are sub-projects of it.

There are many others, but these are the major ones. All distributions of BSD can potentially be used on servers, although some lend themselves to easy dedicated server setup more than others. All are released under a version of the BSD license, making them free and open source software.

How to install Apache on a FreeBSD server

Continuing with our series this week on non-Linux operating system servers, today we will learn about FreeBSD. Its proponents (of BSD distributions in general) call it the most secure and reliable operating system for Internet-connected servers. It comes with several different versions of Apache. Here is a quick guide to getting the one you want installed.

1. Make sure your ports collection is up to date:

# portsnap fetch update

2. Using ports, install Apache (2.2 in this example):

# cd /usr/ports/www/apache22/
# make install clean

It will take a minute to go through the installation, but it will ask you configuration options. You will also need to configure the Apache httpd.conf file as you would on a Linux server. If you would like a more in-depth guide to the specifics of that configuration, see the nixCraft article on the subject.

Source: nixCraft
Photo: Flickr

Disable unused services on your server

Unused services may seem like a non-issue, but they cause your server to take longer at boot, and they eat up RAM that could be used for critical services. This is a cross-platform issue, so Linux, Windows, BSD, and Solaris servers could all potentially have unused services running in the memory.

For example, Linux distributions and Mac OS X often come with CUPS enabled, but if you are using your box as a web server, CUPS, a printing server, is not something you need. Other unused services might include X.org (a graphical window server), bluetooth, hplip (another printing server), nfs (network file system), and many others. Find out what services you are not using and will not need and disable them.

To disable services from starting at boot in Redhat Enterprise Linux, CentOS, and Fedora, become root:

su

and type from the command line:

setup

Scroll down to “System Services” and then remove the star from any of the services you do not need. Tab to “OK”, press Enter, and then tab to Quit and press Enter.

What is named?

Question: I keep seeing the program called “named” running on my server. What is it?

Answer: Named is one of the DNS programs, also known as Bind, which is a free and open source DNS management system. Bind handles all of the DNS for your Linux server and is usually started at boot time and remains running as long as the server is on.

BIND stands for Berkeley Internet Name Domain and was originally created for BSD, although it now runs on most Linux distributions and other Unix-like operating systems. Named refers to the “name” program running as a daemon (or background program), represented by the letter “d”.

Many web hosting control panels have DNS support built in, so you will most likely not need to manipulate Bind from the command line. Nevetheless, it is still good to know something about using Bind, just in case something goes wrong.

What is BSD?

Question: I have heard of Unix and Linux, but what is BSD?

Answer: BSD commonly refers to the the UNIX-like operating system developed at the University of California, Berkley in 1977. It predates Linux and has been used in Unix server environments for decades, in response to the licensing issues of the original and much more expensive AT&T Unix.

Since the original release, several derivatives have emerged, including FreeBSD, NetBSD, OpenBSD, and to some extent, Darwin, which is the underlying backend of Mac OS X. All BSD variants are licensed under a permissive license, which allows for integration with proprietary software. As such it has become useful to both small businesses and large corporations.

Many web hosting companies use BSD-powered servers, and it offers the same security and stability that is expected from UNIX. Most Linux-based software has been ported to BSD, making it virtually indistinguishable to the casual observer. Moreover, BSD systems are known for their long uptimes, and some web hosting experts prefer them over other UNIX variants.

Photo Source: Flickr