In my previous post, we were talking about the danger of hardware failure in virtual machines. Let’s move on to the next…
Danger Two: The danger of interference from other customers’ virtual servers.
There are several ways in which one virtual server can interfere with another, when they’re running on the same node. However, when security is properly implemented, this risk is completely mitigated, and the solution is just as secure as a dedicated server.
A responsible host will have thought out these issues and put safeguards in place to ensure that one virtual server cannot impact upon another. Here are some questions to ask your potential virtual server provider:
- Will I have my own VLAN or are all virtual servers on the same network segment?
This is important, as virtual servers on the same VLAN are on the same broadcast domain. This means if someone enters your IP address in their network configuration incorrectly, they could take your virtual server offline. It also means you’d receive their broadcast traffic. Finally, it means that there is complete lack of firewalling between your virtual server and others, unless a software firewall is put in-place (see the next point for more on this). - Will I have the protection of a hardware firewall?
With a separate VLAN, it’s possible to protect a virtual server in the same way as you would a dedicated server. This means that not only traffic from the outside world, but also to other neighbouring customers, is allowed through only if it meets the firewall rules you’ve set. - Are the kernels shared with the host operating system?
Slightly more complex this one; basically some virtualisation technologies share the host node’s base operating system kernel with the virtual servers, for various reasons, usually so the provider can put more virtual servers on a node. However this means that any kernel vulnerability could mean that a compromised virtual server can effectively take down the whole of the host node, which basically means all the virtual servers running on the node will be taken down too.
It kinda goes without saying that our UltraVM™ cloud servers pass all these tests (otherwise why would we have written this blog!). Take a look at the feature-set, and visit back for danger 3, 4 and 5 later this week.
Daniel Keighron-Foster, Managing Director
This entry was posted on Tuesday, June 8th, 2010 at 7:05 pm and is filed under Helping Hints from our Techies. You can follow any responses to this entry through the RSS 2.0 feed. Responses are currently closed, but you can trackback from your own site.
[...] of “the five dangers of virtual servers”. In my previous post, I talked about the danger of interference from other customers’ VMs on badly-configured platforms. So let’s move on to the next potential [...]