Virtualisation vs Dedicated Servers
Virtualisation of a server is the transfer and consolidation of number of physical servers onto a single more powerful machine able to cope with the increased load. Server designed machines are designed use only a small portion of the total CPU, RAM, and I/O, so it’s an economic choice primarily so that you can squeeze the worth out of your companies hardware investment.
You’ll read some articles that state dedicated servers are “dead”. Not true, dedicated servers still play an important part in any companies set up, be it for isolation security, or dedicated processing power for specific purposes .
Virtualisation has come to the headlines over the last few years via Cloud technology, which makes use of Virtualisation and makes it available over the internet. Virtualisation is a separate entity to the cloud, but Cloud technology makes an excellent partner in providing Saas PaaS technology available to users,
It’s all about the money
Virtualisation is all about economy so as save money, an important consideration to budgets. This may be hardware costs , IT staffing /human resource, or energy related savings. But the initial outlay in buying individual servers will always be higher than virtualisation. Even though you may save costs on hardware, the costs of the virtualisation software and licensing can become high. You may have to treat each virtual server as a physical instance like before, so normal licensing costs for each virtual server stays as same, again this is where the Cloud cross over steps in. Cloud technologies such as Saas (Software as a Service) often incorporates licensing, reducing the outlay to the client. Or looking to specific software that offers advantanges such as Office 365 (multi user licence for small business or corporate)
Performance (the two edged sword part 1)
Take time to understand, usually after reading the following the statement the door is slammed on virtualisation. But, its an obvious consideration that the performance will not as be good if you increase the work load for a single machine must handle. While the virtualization hardware improves by getting faster and better each year, you still have more resources being used with virtualisation. Performance needs for an application should to be addressed on a case by case basis, whether this is a virtualised PC or Server.
The majority of dedicated servers are only using about 35% of their computing capacity (the classic IT rule of thumb) . and is a waste of usable resource which is the main reason companies are looking for virtualization. Trying to get the most out of your hardware can be more difficult using a dedicated server environment.
Tolerant CPU power from the host, be that Cloud or the hosting server for the virtual is the main consideration, the better the processor and available memory the better the virtual environment will sit (and behave on the host)
A standard server that is running one application will be faster than the same server running multiple applications. There are times when a virtual server simply cannot perform like a dedicated server and we all have to determine when that time comes. For example consider a database server a dedicated server wins on performance but efficiency is its flaw, the slight compromise of performance moving to virtual enables other advantages as you’ll see.
Virtualisation products have advanced management tools that help you to monitor and review information quicker across more servers. This can reduce the human resource needed and less 3rd party software that you have to learn along with less errors. When you have more items to manage, the risk of making mistakes also increases.
Dedicated hosting solutions are more complex due to their hardware separation. Hardware management requires more time. For virtualization, many of these items are built into the software package.
The jewel in the crown of Virtualisation is disaster recovery Most virtualisation software comes with a number of features that may increase server up-time. If one virtual server fails, it will come up instantly on another machine. Load balancing is also easier. Many packages also come with their own data backup solutions such as ‘snapshots’ to protect data. In case of Physical server, we have to opt other backup and recovery options. The overall outcome being that what may be weeks of work re=establishing a working server can be reduced to hours or a day in restoring the virtualised copy,
When is it too much (failure points)
Eggs in baskets time, should you have 10 virtual servers on a single piece of hardware and if that goes down, the consequences are obvious. Minimizing these risks may require additional hardware like redundant physical servers and SANS so as reduce the possible risks. This adds more equipment and cost which are the exact point that virtualisation aims at reducing.
We can’t let our entire business shutting down due to a single failure. With dedicated servers we know that a single server failure rarely takes down everything, unless its the domain controller!. Virtualisation increases the risk of a major event when you loose a single server. One of virtualizations selling point is the ability to load balance servers easily. The separation of services could be a good thing for many different configurations.
Security considerations and Cloudy skies
Setting up a security plan for a virtual server environment is easier because you can focus on a universal security model. A more focused approach for overall security across fewer dedicated machines is easier than security for more hardware, right?
Your virtual server might be on the same physical server of another company. This is especially true if you are using a hosting company on a cloud environment. If you are leasing cloud space from a hosting provider look into how your server is protected on the cloud. Usually with SaaS you’re looking for seperate IP address, and non domain access as the two main stalwarts of security. The security of your virtual server depends on many factors and could complicate a few items when dealing with industry regulations.
Ease in IT Expansion
Adding a new server or increasing RAM, CPU, or hard disk is as easy as pressing a few buttons using Virtualisation. The ease of deploying new servers can decrease the time it takes to launch new products and services. When you have to add a new physical server to your environment it takes some planning. You have to purchase equipment and then load the OS, security patches, and plan out physically connecting the server to your network. Using virtualisation you can usually bring up another server within minutes by using a copy of a virtual server. If you are a company adding 10 servers per month then this will be the perfect choice. The virtualization of servers does equal less hardware which can help reducing our net power usage with virtualisation.
Some virtualisation software comes with utilities to assist in moving A to B. Initial shadow copies and further snapshotting of changed data allow you to drip your software over to the virtual environment without any “downtime” loss on the original server. Or, the closure of the existing dedicated server for a time, while copies are taken and restored to the virtual allow for parallelism in that you can compare the two side by side and should there be any performance issues then going back to performance monitoring will allow you to fine tune the system offering more of the required resource.
Virtualization advantages out weigh on the whole the disadvantages be that from the PC to a server. The configuration and migration being the overall out lay. What you end up with is an expandable system with a degree of portability that’s easily maintainable. The key is resource of the hosting machine be that a PC for the Virtual XP that windows 7 offers, to the VM Ware product sitting on a five year old server.
But, is it the right thing to do? That’s entirely down to the client, one man’s meat is another man poison is the old saying. The cheers from IT having less to mantain, may be drowned by the moans of users grumbling at response times reduction, and the server that runs the virtual (if badly set up or is itself limited in resource). Building your virtual fort on a soft ground (networking issues, low in efficient CPU on hosting server) may contribute to negating the advantage