Pros and Cons of Virtual Private Servers
by Jimmy Martin
Advantages of Virtual Private Servers
Price - A VPS is cheaper than a dedicated server, as the costs are shared between dozens of site owners.
Configurability - As a VPS acts like a dedicated server, you can install any software you want, and make sure that your VPS is ideally suited to your needs.
Reliability - The hypervisor program makes sure that no one VPS can hog all of the server's resources. It also prevents a website from crashing the entire server. If a website crashes, it will only bring itself down. The other websites on the server will keep running. A VPS will usually be hosted on a high-end server, with very reliable components, minimizing the risk of hardware failure crashing the server.
Simplicity - A Managed VPS, where the hosting company looks after security patches and software updates for you, is almost as simple to administer as shared hosting. However, this is more expensive as you are paying somebody to do the hard work for you.
Performance - Although you are guaranteed a certain amount of memory and processor time for your VPS, if your site experiences a sudden burst of activity the hypervisor will temporarily assign you more resources. This is possible because it is unlikely that all VPS's on the server are using their full quota at all times.
Disadvantages of Virtual Private Servers
Price - A VPS is more expensive than shared web hosting. There are fewer VPS's on a server, so less people to share the cost. Each VPS has its own software, so it is not as simple for an engineer to install updates to all websites at once, and if you use specialist software you will have to administer it yourself or pay for support. A Managed VPS will have security patches installed for you, but costs extra. An Unmanaged VPS is a lot cheaper, but you must do all security upgrades and software installation yourself.
Complexity - A cheap, Unmanaged VPS is almost as hard to administer as a dedicated server, and is best left to experts. If you are unsure you should always opt for a Managed VPS.
Performance - If other VPS users on the same server as you regularly use up all of their allocated server resources and more, there will be no extra resources left for your site if there is a sudden burst of traffic. VPS webhosts minimize this by monitoring each VPS for resource usage, and asking heavy users to upgrade to a more expensive hosting plan with fewer VPS's per server.
Next we will look at the high end of web hosting - Dedicated Servers.