An emerging technology that’s easy to overlook in the Web space has been virtual servers. The word virtual has sort of become a “throw away” word in its overuse and in the companies where the Web is “owned” by Marketing departments it can be easy to overlook the value of this technology. IT departments in mid to large sized companies have almost certainly tested these types of environments to varying levels of success and have weighed in on how much to leverage this technology.
For those less familiar, virtual servers are the ability to take one physical server and create virtual “copies” of server operating systems and applications. These virtual servers then can then all run simultaneously on the one physical server, but can be independent of each other in their configurations in that installing other server applications on one virtual instance does not impact the other virtual servers. Unlike shared hosting environments – you can reboot each virtual server separately – leaving the other virtuals running without fear of bringing down other web sites on the server. The virtual server management utility then allows the administrator to allocate RAM memory to each virtual server and continue to install other applications and tighten or loosen security on the server applications without worrying about how it will impact the other virtual server instances on the physical machine.
A simple model of how this could be best leveraged is that one physical server could be allocated to manage four or more virtual development and staging environments have 500 MB of RAM allocated to each virtual instance. This amount of RAM may be below the recommended RAM for the applications running in a production server instance, but since it is a development or testing server, slower performance may be acceptable since there isn’t really a full “production” volume of Web traffic.
The benefit here is that you can make better use of one physical server for multiple server environments without having to buy physical hardware in each instance saving quite a bit of money on hardware. Licensing of the server operating systems and databases will still need to be accounted for in that you may end up running five to ten or more versions of an operating system and may need to license each separately unless you use some volume licensing or developer licensing (like MSDN or Volume Licensing from Microsoft). If the intent is to run enterprise Web apps like Content Management, Document Management, or eCommerce systems – those would all then incur additional licensing fees as well.
Again the benefit here is that rather than setting up a physical server for each:
- Development Server (often multiples are needed for enterprise Web applications, perhaps one for the CMS – one for the DMS and one for the eCommerce platform, etc.)
- Staging Server (for each of the above types of application)
- Production Server (perhaps multiples depending on site traffic for load balancing)
For illustration sake – let’s assume you have budget for three physical servers (this hardware will generally run anywhere from $5,000 to $15,000 per server depending on bells and whistles). Rather than allocating one machine for development, one for staging and one for production, you may be better served to setup one physical machine with multiple virtual instances of development and staging servers and the other two machines setup for production environments and load balancing to handle higher volumes of Web traffic.
Hopefully, to some degree, we’ve illustrated the cost benefit so far, but we haven’t even touched on the benefit to developers and server admins yet. Setting up a Windows Server 2003 environment can take a half day to full day or more of time installing the OS and “Service Packing,” patching and configuring it etc,. With virtual servers, a developer or admin can “save” the first server instance that is built as a template for other environments in the future so they won’t have to redo all that effort the next time they need to build a similar environment. Essentially a fully built, patched and configured Web hosting environment can be configured one time and saved so that you can then create an instance where SQL 2000 can be added to one server instance and then you can go back and create a copy of that original server instance and then install SQL 2005 and then test how applications will work on one database instance vs. the other without having to redo the work of configuring Windows Server 2003 each time.
Some things to consider and watch out for is whether you’d want to setup one physical server with three virtual servers running on it – your dev, staging and production. This may not be the ideal scenario in that while RAM may be allocated accordingly (500MB to development, 500 to staging, and 1GB to production for example), you may run into some performance issues as changes in the staging server or processes (like search application indexing within a CMS or DMS) may tie up access to the server hard drive and negatively impact performance of your production server if it is on the same physical machine. Also, if there are problems with the physical server it impacts all three of your “servers” vs. the more ideal scenario of having production dedicated to one physical machine independent of changes to any of the dev or staging environments. If you want to still save money by having virtual servers running multiple production environments that is still probably OK, but at least consider the idea that the virtual instances on that physical machine are all production vs. a mix.
Aware can work with you and your IT department or ISP to determine the best initial use of this technology.
Aware is working towards leveraging this technology more and more for our client’s benefit so these virtual development servers can then be moved from developer to developer and, in some cases, archived for future use. For example, Aware can start a Web development project by using our pre-built virtual development space that has a working template of the required environment to then start development right away. This methodology saves our clients thousands of dollars on each project by not having to setup development environments from scratch each time.
Please see the other resources in this article for more information on this topic – they can get pretty techie pretty quickly, but try to grasp as much as you can – it’s worthwhile...
http://www.microsoft.com/windowsserversystem/virtualserver/default.mspx
http://www.microsoft.com/technet/try/vhd/faq.mspx
http://support.microsoft.com/default.aspx?scid=kb;en-us;903748