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The Trouble with Virtualization - Cranky IT Staffs
lgmac writes "A new survey on the results of Enterprise use of virtualization shows that the process is seeing wide and appreciative use. Technical hurdles are obviously the biggest problem facing corporate IT shops. Just the same, political squabbles among IT staffers fighting for turf after being forced to work together in new ways seems to be a going concern as well. 'Technical woes rank higher--to be expected when CIOs deploy a new technology such as virtualization. However, the politics pain many of you. Remember, virtualization not only asks people to cede some control over their physical server kingdoms, but also asks IT experts from different realms to work more closely together.'"
*facepalm* I sometimes forget how stupid people can be.
Personally, what I've found to work great with virtualization is consolidating all the dozens of little low-load servers. It helps with power consumption and heat output, as well as hardware costs. For a major company-wide high-load system, virtualization is absolutely not what I would be looking at. It's also fantastic for testing environments.
I don't know about you, but my servers run on the power of cotton candy and happy thoughts. -Anonymous Coward
VMware has multiple ways to balance and protect resources. You can set hard limits on VM resource utilization, ensuring that one machine can never take over a certain percentage of CPU, memory and even network bandwidth. VMs can also be given "shares", which determine priority over resources. In a contention for resources, the VM with the highest number shares is given immediate access to what it needs, with the lower share VMs splitting what's left over. This is the recommended way to handle it, as it gives you the best overall hardware utilization across your entire implementation.
Starting in VI3, VMware also introduced the ability for VMs to migrate automatically across an entire farm of hosts, based on server load. In my experience, with very little tweaking, VMware does a very good job of fairly balancing resources.
ESX3 is Linux based however ESX3i is not. It is a pure hypervisor checking in at about 32MB.