The ability to generate software-only instances of an operating system (virtual systems) promises freedom from hardware concerns and an endless amount of no-cost capability, right? Not exactly, but it holds great promise in certain circumstances. Here's my fence-sitting take on the positives and negatives of this new technology.
POSITIVES:
1. Reduced electrical cost (less power supplies to feed)
2. Reduced equipment inventory and space
3. Reduced spare parts inventory and space
4. Simplified rebuild administration (ability to spawn new instances quickly)
NEGATIVES:
1. Heavier hardware requirements for remaining computers
2. Ability to run more systems = greater demands on the admin's time
3. Related to above: possible management denial that virtual machines need attention
4. Related to above: multiplicity of installs may lead to security holes
Reduced cost and space has been the main attention-getter. The more purely electronic and virtual an organization, the less material maintenance is needed on all fronts (not that one could totally get away from it). On the downside, an operation might need newer computers and networking to handle the throughput and ram demands. And responsibility creep might chase away admins who see more systems assigned to them while a manager might be tempted to overrule objections since the new machines (that require configuration, patching, security analysis, monitoring etc. etc.) are "only virtual". And if many instances of disparate OS's are forgotten about after a few rounds of testing, a break-in artist could find abandoned and unpatched opportunities for setting up shop.
I think the obvious conclusion is that whether or not virtualization works is a function of the skill of the administrator(s). To a lesser degree it's a function of whether or not the hardware STILL present can handle the loads. And we should all remember that if more systems are running on fewer devices, then backups (both software and spare turnkey machines) are rendered even more important than they've traditionally been, which is a lot.
