What do you all think about Virtual Servers?
Well definitely off topic, but since I've played with some at work, and it cna lead to interesting stuff regarding SM computer tech.
First you have to be aware that there's 2 kind of Virtual servers :
- Virtualization on top of the hardware. ( Xen for example )
- Virtualization on top of an already running OS. ( VMWare, Virtualbox )
There's also something in between from Oracle ( well from Sun initally ) : it's called zones.
In the case of the first one, you have a small hypervisor that is used to virtualize the hardware so that all the OSes on top can see it ( well see the part they are allowed to see ).
In the case of the second one, the hosting OS just virtualize everything and the hosted Os uses ressources provided by the host.
As for the in between... the hosting OS is the Solaris kernel ( and just that ), and the hosted OSes have to be Solaris or Sparc Compatible Linux )
I've never used the first one... I never had in my hand a server big enough to make it worth to try.
I used the second one many times, as it's how we did the initial install of a telecom system at work :
We have a linux virtual machine with a jumpstart installed on it started on our PC, connected to the system to install ( virtual ethernet port from the virtual machine tied to the regular ethernet port ).
All the initial configuration is performed through the virtual machine... then once the system has jumpstarted, we can stop it and use our PC to finish the job.
I've also used the Sun/Oracle In Between a lot, as it allows to partition an unix server in such a way that people can crash their personal server without impacting the other virtual servers... At least as long as they have no access to the root zone ( but I'm not crazy enough to let them have access to that, since crashing that zone would mean crashing every virtual servers on the system ).
The nice bit of this one is that it's easy to maintain, it's easy to create and remove, and you can do it even on old Sparc Systems. ( as long as they can install Solaris 10. )
The not nice bit, it's 100% proprietary : SPARC servers ( with Sparc Processors ).
Since I've moved to other things ( aka : Internet Backbone Routers ) 3 years ago, all the above might be outdated, as tech progress quite fast in that domain.