Michael, we are using a vCenter cluster for our VMware hosts. In this way, the vcl knows only about a single VM host, when actually there are several ESX servers behind the scenes. VMware then manages all of the resource and load balancing -- the VCL isn't really designed to manage this. This means that when one server is consuming too much CPU or memory, then the VM is "vMotioned" to another physical host.
The downside of this is that it requires the more expensive (Enterprise) VMware license; also, depending on how you manage your datastore disk extents, you may run into VMware's 2TB disk limits (unless you are already using vSphere 5) -- note that you will need to use shared SAN storage across all of your ESX hosts in order to enable VMware's Distributed Resource Scheduler (that is what manages the load balancing). Aaron Coburn -- Aaron Coburn Systems Administrator and Programmer Academic Technology Services, Amherst College [email protected]<mailto:[email protected]> On Oct 23, 2012, at 10:38 AM, Michael Jinks <[email protected]<mailto:[email protected]>> wrote: Hi List. We designed our deployment with the idea that we could use the VM limit setting in the Virtual Hosts configuration page. Since that setting doesn't actually do anything, now I wonder, what are other sites doing in order to manage load on your virtual hosts? Related to that, any tips on doing load testing to see what our environment can handle given our expected work load, hardware setup and so forth? When we thought we could adjust things on the fly with a slider, I was less concerned about knowing in advance what a single host can take. Now I realize we'll need to be very careful in advance when it comes to assigning virtual computers to hosts, so any tips on planning and testing that would be welcome. Thanks. -mrj -- Michael Jinks :: [email protected]<mailto:[email protected]> University of Chicago IT Services
