As time passes, the base of Linux users is growing in the data center, desktop, and even embedded electronic devices. Numbers from industry analysts point out that Linux server shipments have shown double-digit growth every quarter for over two years. In many cases these servers are being used for expansion or new projects. Inevitably they will be put into service to replace systems that once ran Unix or Windows.

In these cases there is usually an event like a hardware upgrade due to obsolescence or capacity concerns, software maintenance renewal, or other occasion that drives the migration. Rarely do we see a complete replacement of all legacy systems; it's commonly done piecemeal where one part of the infrastructure has been migrated in lieu of renewing an investment in other systems. This means migration to Linux. It also often means adoption of open standards that for the most part is a prime consideration for the open source community. Open source without open standards bears less advantage than a fully open system.

Linux migration is usually a matter of expansion, adding Linux into an increasingly diverse environment. Desktop PCs may be predominantly Windows, while file servers and application servers once hosted on Windows or even Novell NetWare might soon be hosted on Linux. In this case there are two hurdles that you need to overcome, especially if there is a need for communication between systems. The first is the obvious hurdle of moving from one system to another. This is a short-term problem. It's usually very disruptive and requires a considerable amount of planning and staging, though it's not especially unique as you face many of the same problems moving from one version of Windows to another or from one brand of Unix to another. The second problem is longer term and involves interoperability with existing systems. To lessen the burden in this area you should be planning well before a migration. The consideration I believe is most important is whether your systems lock you in and make it unlikely you can easily change vendors should you become unhappy with and want to investigate others. This applies to your data and network services. For example, could data stored in DB/2, Sybase, or Oracle be stored in MySQL or vice versa? Does one system have features you can't live without? Could documents originally authored in Microsoft Office be read in OpenOffice.org? If a new version of Windows becomes available, does it still allow you to access your Samba file system hosted on Linux? These are all questions you should be asking regardless of platform. For example, using Apache on a FreeBSD server is a fine choice, but if you decide that Red Hat offers a good value, can you move from one platform to another? The answer is likely yes. Does the same hold true for Web applications developed on Microsoft's Internet Information Server?

My advice is to adhere to open standards and portable file formats that are more easily migrated later on. Even if you decide to stay with one vendor, it's much better for you to select which solutions to use rather than your vendor making that choice for you. I suggest looking at things that are going on today in your enterprise. On the desktop you are likely using Microsoft Office. Their next-generation file formats are XML and intuitively should allow for easier collaboration between Microsoft and OpenOffice.org users. However, watch closely to make sure that they really do facilitate the sharing of files and that the hype is not the result of a clever PR campaign. Another thing to be wary of is the potential of a new feature in Microsoft's yet-to-be-released Vista operating system: encrypted file systems. Since the product has not gone live, it's hard to understand how this will affect cross-platform enterprises. My understanding is that this feature would likely include a level of encryption that protects the data on the hard drive (for example, the one on your Linux laptop). The idea being that if your laptop were stolen, it could not be booted under another operating system and the data would not be accessible. At first glance this sounds like a valuable feature. However, the question is: Would this prevent you from legitimately accessing that data from another operating system (like I do on my dual boot Windows/Linux laptop). In fact I often help Microsoft users migrate their data from an out-of-service Windows PC using a bootable Linux CD and a network. Will I still have this option with future products? Since this new technology prevents the bad guys from getting my data, I wonder if it also prevents me from accessing my data in a way that I choose? Is the encryption technology open source and does it allows me to authenticate my data from systems other than Windows? Does that make it possible for me to share files between systems that aren't licensed to use this new cryptology technology? I'm unsure of the answer.

I also worry about the inclusion of Digital Rights Management (DRM) technology in hardware. For example, DVI connections that are present on many modern graphics cards are very similar to the HDMI (High Definition Multimedia Interface) cables that are being used to combine audio and video into one cable for home entertainment equipment. Eventually, computers will use this same interface. Now here's a bit of trivia: the HDMI standard includes an element called HDCP (High Definition Copy Protection, developed by Intel) that does little to add value to my personal experience (I'm sure the recording and movie industries will offer some statistic about how reduced piracy keeps prices lower for me). However, it could mean that if I choose to use a "standard" graphics card with a standard PCI-E interface, I also must make sure that they adhere to less obvious standards buried within my hardware should I want to watch a DVD or HDTV broadcast. Does HDCP add value to me personally? Does it help me get more enjoyment out of my system? Should I be concerned about what's going on within the widgetry of my system? I would think so.

My point in mentioning these things is not to cause you any undue worry or to preach doom and gloom. My hope is to make you aware that while you continue to adopt mainstream technologies, you may also unknowingly be adopting features that lock you into a product's technology. Some of these features will have benefits that will be useful to you; just make sure you are getting what you bargained for. Also, what happens if these technologies add an additional point of failure? For example, the reason I know so much about HDMI is because I recently bought a plasma TV and while running cables from my HD receiver to my A/V receiver to my new TV, I found out that the receiver or the set top box didn't properly implement the standard. The result was that the copy protection software inhibited my ability to legally use my equipment. HDCP never came up in the sales process nor were the installers of my system aware of the potential problem. Take the same situation in a different content: What happens if data stored on your Windows server becomes unavailable to your Linux servers because of some obscure DRM scheme? Does it shut down your operation? Does it add unnecessary complexity and inconvenience? These are the questions I would be asking before I made my next investment in new technologies. The freedom to migrate is one that I believe to be more important than the actual act of migrating. You see, I have made my decisions and continue to make them but do so on my terms, not that of vendors that are conspiring to lock me in. In the future I don't know which conventions might be widely adopted that would prevent me from using legally purchase products in a reasonable way (of course, the consumer's version of reasonable way and the vendor's are bound to be different). What I do know is that I need to be vigilant and watch for these gotchas, and take steps to avoid them. I would advise you to do the same.