Forum OpenACS Q&A: VServer vs. Xen
I like these two:
- move running virtual machines to another host without stopping them
- pickle a virtual machine's state to disk and resume it later (wonder if the paused server can be moved easily to another machine as well)
On the Vserver site I found this wish from Cathy:
"Biggest wish: more resource allocation abilities, especially for memory."
Is that still the case Cathy? This is one of the positive things I read about Solaris Zones (nice allocation between zones... e.g. if one zone needs RAM and anothers are not using it all, that machine can take adavantage of the situation). Wondering how Xen deals with this.
Also, here is a Xen limitation that could be important for heavy trafficked sites: "Xen can currently use up to 4GB of memory. It is possible for x86 machines to address up to 64GB of physical memory but there are no current plans to support these systems: The x86/64 port is the planned route to supporting larger memory sizes." How much RAM does a site like Galileo typically need? On the other hand, we do have a load balancer for clinical applications and could possibly use it to distribute load to various Xen instances on different physical boxes.