Linux Servers

I start by covering the times when you can use Linux, then the times when its not a good idea then finally covering some of the special function servers that Linux is ideal for.

When to use UNIX/Linux

Before continuing you need to understand what non-Windows servers in there current state of development are not production ready to replace all Windows installations. Currently I recommend the use of these alternatives for, file, print, WEB, gateways, routers, firewalls and for some specialist servers.

• Cheaper. This is one of the most important advantages of using an alternative operating system. When you build a Windows server, you have the huge cost of over AUD$2000 (price from Harris technology, Sydney) for Windows 2000 server, which if that expense is not bad enough, that only gives you client access licenses for 5 users, for each additional user you need an addition "Client Access License" which costs yet more $$$$. Even worse than that the Microsoft Licensing system is very complex, so if you want more info on that one give Microsoft a call. I have just done a mid sized Windows based installation an the licenses took three days on the phone to Microsoft to sort out and also cost over AUD$40K.

  Now on the other hand with Linux, there are no licensing costs at all, no OS cost no client licenses etc, its all free, just download from the Internet. Now thats a advantage yes?

• Stability. This is one of the most important things with a server, lets not beat around the bush, Windows crashes all the time, even Windows 2000 which is far better than NT was, still crashes more often than anyone would like, and yes thats on good high end Compaq, IBM or Dell hardware. I will not go into the many reasons for this, see the Microsoft web site for more on this one.

  I have only seen one Linux machine crash and that was a hardware issue. If built right, on good hardware, from personal experience Linux is far more stable than Windows.

• Security. This another biggie, lately there have been several well known security problems (think code red etc) that only affected Windows machines with IIS, even without IIS there are security alerts all the time that are Windows specific, not good?

  Now with Linux its more secure than Windows yes, but there are still problems, remember the recent zlib mess, there are just less of them. Even with the problems that do occur I use nothing but Linux for firewalls, using Windows servers for this is just too risky and expensive.

• Hardware. With every new version of Windows, the minimum hardware requirements are increasing all the time, and even with the costs of hardware coming down fast, in many cases to upgrade the OS or in some cases load a service pack, you need to upgrade the server to take it. Think never ending upgrades, and expense.

  Using Linux you can get away with less powerful hardware, but not much less powerful than you need for Windows. Some people will tell you that its possible to run a Linux server with a 386 and 4MB, well sure its possible just not much use when running. To be realistic use the same hardware as Windows, the big advantage comes in the upgrades to the OS, the need for additional hardware in my experience is minimal or any at all, which results in longer usable life for your hardware which saves $$$. Do not let this put you off contact me with you requirements and I will see what use can be made of your existing hardware, in many cases something can be done to avoid the high expense of a new server.

• Performance. This is a real hot potato, Microsoft a while back released figures that proved that Windows was faster than Linux, then others released numbers showing the reverse. My only comments on this, are based on client feedback, which has shown in all cases, that the users feel its faster than there old Windows servers, usually on the same hardware. One site I manage has 2 identical servers one NT4 the other Linux, they report that the Linux server is faster.
• Administration. Now this is one where on the surface Windows has a advantage in that every server admin task has a nice pretty graphical tool, and also there are many remote management tools available from Microsoft and other software houses. In addition to this there are more people out there with skills to manage a Windows server than a Linux one.

  Sure this all is true, but I counter this advantage by using Webmin on every server I build, install or manage, this free open source product provides web browser based administration for all the normal server functions. Its very good and developing fast to the point where its actually in my opinion easier to manage a Linux server than a Windows one.

• Support. This is another area that on the surface Windows has a advantage over Linux, in that Microsoft provides commercial support, and yes the level of support for current products is high, if in most cases chargeable. Now the bad news, like all software companies they have a policy to terminate all support for older products, which implies that you have to keep upgrading to maintain support. I see why they do this, its not economic to support every product for ever, but is a cause for concern, at many smaller companies who are quite happy with, for example Windows NT4 server, but need a patch or new driver to support, say a new hardware device, Microsoft is not going to help, they are going to say "Upgrade to Windows 2000 server, NT4 is not supported", which again brings me back to my hardware point.

  Now with Linux this is not always the case, sure the OS and Apps are constantly being upgraded improved etc, and older ones are not supported by anyone, but in this case you have the option of talking directly to the author. In addition to the accessibility of the author, the majority of upgrades do not need additional hardware which again brings me back to my hardware points. As always contact me and I will help you with this one, whether its training your own staff or supporting the new server for you.

• Virus/Trojans. This is another big advantage over Windows, Linux and UNIX in general is immune to the majority of Windows viruses. Its just too different, for example the recent "code red" problem is not able to infect Linux, nor are any of the macro viruses. Today this is true, but those "people" who write this kind of thing are not likely to ignore other OS for ever, indeed there are some Linux virus out there, but they are rare. Even with the level of virus out there some of the anti virus companies have released anti virus products for Linux. At the moment I am testing the "network associates" products.

When Not to use Linux

I hope that the above have helped you get a high level understanding on the use of Linux servers in place of Windows servers. Now there are some instances where you will have no choice but to use Windows, and its only fair that I also detail these.

• Application servers. This class of server is one that runs specific application software such as SQL server or is part of a SMS installation. In this case these products will only run on Windows servers, although in the case of SQL there are options for alternative SQL servers such as mysql. The rule of thumb is that if its a Microsoft product or another software houses product thats tied to a Microsoft Server platform then its a Windows server or nothing at all.

  As I said in the overview, at this time and being very realistic Linux servers are for general file and print serving, WEB, and some niche applications.

• Server Management. If you are a company that uses one of the server management systems such as SMS, then I am sure this will not work with a Linux server, and in the case of a Microsoft product they are not likely to ever support non-Windows servers. Other vendors like IBM may offer support for Linux, but you will have to check with them before going for a Linux server.
• Support. If you have a large investment in in-house support expertise and do not want to have to re-train personal to a new system, then you have two choices, these are to have me do the management for you either on a as needed basis or stick with Windows. I can help you with this.
• Hardware support. This can be a problem with Linux, hardware support, while there are a vast number of drivers available for Linux, there are more for Windows. Now this has caused me severe problems on workstations, is less of an issue on server, but is still one more thing you need to take into account when considering alternatives to Windows. contact me and I will go into this in more details for you.

Special Function Servers

In this final section I talk about some of the special function servers that you may need, together with your options for these, both Windows and UNIX/Linux. I cover some of the essentials of life, like DNS, DHCP, Email, VPN and Streaming Media. I have not included these servers in either the use or don't use Linux sections as you can now use either, although personally I would always use Linux as a first choice for each of them.

• DNS and DHCP. Network services like these started out fully in the UNIX world, which although Windows NT4 and 2000 are capable of providing them, I feel they should stay UNIX/Linux, indeed every single installation I have ever done of either of these has been UNIX based.
• Email. Just like DNS and DHCP, email started life on UNIX, but no longer only UNIX, now its also available on Windows, with server applications such as Microsoft Exchange, which is a very capable solution that runs on Windows NT and 2000 server, and is complete with all the usual graphical administration tools. The downside of this is cost, Exchange is not cheap, needs client licenses, a power machine to run and has questionable security.

  On the UNIX/Linux platform there are a large number of Email server solutions, most are free, very few require any kind of client licenses, and the hardware needed is not usually excessive. The downside is that most of these email servers are generally not as easy to setup and manage as a Windows server solution. Now before you run out and buy Exchange, all is not lost as there are now modules for webmin browser based administration tool, which makes running a UNIX/Linux solution as easy as Exchange. Another advantage of using a UNIX/Linux mail server solution is the performance, and scalability, from personal experience you need much less hardware to support the same numbers of users under UNIX/Linux than is needed for a Windows server, which means you can support more users on the same hardware.

  The final choice on this one is yours, just take into account the points I have raised to see how either fits your needs. Failing that contact me for help.

• Remote Users/VPN. This is a real growth area, I get inquiries for provision of remote access for home workers all the time, and until fairly recently choices where more or less limited to Windows NT4/2000 server, or high priced UNIX solutions. Now things are changing there are good quality open sourced applications that can provide the same services with the same or better levels of security. For example its now possible for you to use a mixture of Windows/UNIX/Linux as a client operating system, if you are running a VPN with Microsoft PPTP protocol. Thats good news but is still not the really good news! which is now you can also use UNIX/Linux as a PPTP server and support the same variety of clients.

  Another development, is the increasing use of "Network Computing" via products like "Windows Terminal Server" or "Citrix", both of which are very high quality/priced, Windows only applications. Well these are not the only real choice for this type of technology, you can use VNC which supports UNIX/Linux/Windows clients from a UNIX/Linux server, and is open source.

  As yet I have not personally used VNC, so cannot comment on how well it works, but from talking to those who have, they tell me that the functionality is along the same lines as the Windows products.

• Streaming Media This is one area thats showing surprising growth in demand. Last year I only got a single inquiry, now in the past 2 months 10+. So with this increased interest, I have researched the subject under Linux and found, that yes its possible and no its not a horribly expensive thing to do. So here are the results so far.
  • Audio. Streaming MP3 audio could not be easier, there are many choices for this, but by far the best is gnump3d which has to be the simplest streaming server I have seen to install and configure but without compromising on functionality. As for the costs, there are none, its GPL licensed, and does not need huge amounts of hardware, my test system is a old P90 with 32MB. I currently testing for suitability for use as audio help system for a clients intranet, so expect updates soon, both for this type of application and for general use, stability etc.
  • Video. I am still testing some of the options, with the current front runner being Videolan. When my tests are finished, I will update this page, and also write a detailed review of its functionality.