Virtual Private server questions

1. What's the difference between a virtual server and a dedicated server?
2. Why would I choose a virtual server?
3. Will I have performance problems on a virtual server?
4. Is there a difference between VPS & VDS?
5. Can I upgrade from one VPS to the next? What's involved?

1. What's the difference between a virtual server and a dedicated server?

   In a dedicated server the operating system is installed directly on to the host machine. The server hardware is only used for a single purpose.

   For a virtual private server, a separate piece of software is first installed onto the host machine, and within this software virtual machines are created. In the Anchor virtual private server service, the behaviour of each virtual machine from an operating system and configuration perspective is identical to that of a dedicated server. If you are only using remote management tools to control the server (most common) you would not be able to tell the difference.

   A virtual server and a dedicated server will have different performance characteristics due to the presence or absence of the virtualisation layer. Most entry level dedicated servers utilise entry level hardware, virtual servers on the other hand are deployed on host systems with very high end, high capacity hardware. This is offset by the fact that the hardware is shared amongst multiple servers.

   In summary, a low end dedicated server will generally perform in much the same way as virtual server. Matching performance characteristics more exactly will depend on the hardware allocations for each.

2. Why would I choose a virtual server?

   Our page on why choose VPS hosting provides a more detailed answer, but in summary:

   • Lower cost entry point for a stand alone server
   • More flexible, rapid and smoother performance upgrade paths
   • To gain access to high end server hardware on a relatively low budget
   • You require independence and control of a standalone server but not the performance
   • It makes more efficient use of resources and so is environmentally friendly

3. Will I have performance problems on a virtual server?

   No, provided that your expectations are realistic. You cannot expect are service costing $80/month to perform the same as a service costing $175/month. The same restrictions apply to virtualised servers as they do to dedicated servers. If you ask the server to do more work than it is capable of the performance must suffer.

   If you monitor the load on the server and continue to make the appropriate capacity upgrades, acceptable performance levels can be maintained.

4. Is there a difference between VPS & VDS?

   There seem to be three commonly used terms to describe hosted servers which are provisioned utilising virtualisation:

   • Virtual Server
   • Virtual Private Server
   • Virtual Dedicated Server
   The terms are often used interchangeably and so you cannot rely on the name alone to know what you're buying. There are a number of different vendors of virtualisation software and each of them takes a different approach to implementation. Broadly speaking there are two major groups which we refer to as full virtualisation and operating system virtualisation. Full virtualisation is more resource intensive but is the only approach that ensures your "virtual server" behaves from a configuration perspective exactly the same as a traditional dedicated server.

   The Anchor virtual private server is based on a full virtualisation approach using VMWare.

5. Can I upgrade from one VPS to the next? What's involved

   Yes, you can upgrade (and downgrade) between VPS plans. For Linux based servers the upgrade requires only a reboot. Disc resizing is carried out whilst the server is live after the reboot. For Windows based VPS's the upgrade requires a reboot and an outage of around 45 minutes (depending on the amount of data stored on the VPS) to allow time for the disc re-sizing to occur. Due to the outage length Windows VPS upgrades are performed outside of business hours.