A key aspect of VPS internet hosting is its virtualization capabilities. With VPS, the hosting provider divides each physical server into multiple smaller virtual servers with private and dedicated RAM and hard drive space. This provides site owners with a more isolated hosting environment without disruptions from other clients sharing server space.
It can varies a lot from VPS hosts to hosts. This can be a little confusing because unfortunately many hosting providers differ in their definition of “managed hosting”, and some providers have “semi-managed hosting”. So if you’ve determined that you need a managed VPS (which is positively the way to go if you are not comfortable with running a Linux server), you must contact your potential VPS service providers for the details or look at the specific tasks that your managed provider will and will not perform.
Uptime: What is their SLA regarding up-time? Can you afford to have your business down for days? You should always aim for 99.9% uptime since a 99% uptime is equivalent to 4 whole days of downtime (for a yearly period), which is not acceptable in today’s competitive market. This report by hyperspin monitors the uptime of various hosting providers and you can use it as a guide before deciding which one to choose.
Recently, we've added more-formal uptime monitoring to our review process, and the results show that most web hosts do an excellent job of keeping sites up and running. Even if they get everything else right, sites with uptime problems aren't eligible for high scores. All services suffer ups and downs, sometimes for reasons beyond their control. Those sites that fail to address the problem in a timely manner are penalized accordingly.