So from "the other guys" we get the following:
- "at the root of virtual machine performance problems is file fragmentation." Well, maybe yes, maybe no. Do we think that fragmentation is the cause of many performance problems? Of course. But we're not going to sit here and tell you there are no other performance considerations in a virtual environment, just as we wouldn't say that for physical environments.
"the only real solution to optimizing virtual machine performance and reliability is a fully automatic defragmenter, one that is constantly taking care of the fragmentation problem." Well. Besides the caveat from above, I would alter it to the following: "the only viable defragmentation solution to optimizing virtual machine performance and reliability is a fully automatic defragmenter that is virtually aware. Without virtual awareness, your defragmenter will very likely do more harm than good."
Here's the deal. As Erwin Solis clearly demonstrated in our recent Webinar on defragmentation in a virtualization environment (ESX, Hyper-V, etc.), automatic defragmentation without virtual awareness is a road to performance problems. Solutions like VMware's vMotion address resource contention at the virtualized machine level. PerfectDisk 10 Server Virtual Edition addresses it at the virtualized software level. There are finite resources to go around. Treating a virtual machine like a physical machine in this environment, with the goal being to try to solve fragmentation and performance problems, is going down the wrong path.
With the PerfectDisk solution, you not only eliminate resource contention, but increase the resources available for your busy virtual machines. Without that awareness, the idle machines are basically stealing resources needed by busy guests, defeating the purpose of what you were trying to accomplish and very likely causing new performance problems. Not smart.
In Erwin's example, he shows a fairly loaded hypervisor with a couple of servers -- one busy and one not. The results without virtual awareness? Not pretty. Or as Erwin puts it, "it's like a man trapped inside a room with no doors; the room looks large, but he doesn't see the reality - he's trapped in his box."
To see and listen to the 30-minute webinar, Defragmentation in a Virtual Environment," go here.
Automatic defragmentation without virtualization is a fool's errand. Test yourself and see.
Get out of the box and see your whole world -- virtual and physical.