by James E. Gaskin - Mike Laverick travels the globe training people on VMware and running his busy Web site www.rtfm-ed.co.uk about virtualization. Today he offers some insider tips from his new book VMware vSphere 4 Implementation.
First, think of multiple virtual servers on a physical server like Dr. Who's TARDIS machine: bigger on the inside than the outside. Laverick says users new to the world of many virtual machines packed inside one physical machine sometimes get confused between which is which, whether a disk is physical or virtual, and whether the disk adapter for that disk is physical of virtual.
When jumping down this rabbit hole, reach out to local user groups. No matter if the group is general or specializes in VMware, Microsoft Hyper-V, or Xen, the members will gladly help. Remember the early days of PCs and the user group attitude? Still there in the virtualization community.
Second, don't let your initial hunt for "low hanging fruit" using virtualization lock you into only replacing legacy servers or underutilized servers. It's politically smart to offer some quick benefits when starting virtualization to get approval, but don't stop there. Laverick has seen medium sized companies running 100 percent of their servers in a virtual mode. Yes, every server a virtual server. Some industries, like financial services, may have some old-fashioned regulations that tie accountability to specific hardware, and you must follow those rules. Everything else, including Exchange, Oracle, and SAP servers, are fair virtualization game.
This area still has room for users to push beyond what the vendors offer. Laverick said early backup for virtual machines were hand-built by users to copy certain VMware files here and yon for protection. Now, all the virtualization vendors have backup programs. They do the same job, copying virtual machine system files, but they have nicer interfaces.
Another area where users pushed the vendors was HA (High Availability). Laverick used to write his own scripts to check the heartbeats of various virtual machines, and now VMware has an HA toolset.
Estimates are that only about 15 to 20 percent of IT resources that could be virtualized have been, meaning the market will continue to expand. Early adopters have paved the way, and no company should need education on the value of virtual servers today. Since the new buzz now is about VDI (Virtual Desktop Infrastructure), virtual desktops may become the norm rather than the exception in a few more years. After 10 years watching the virtualization market, Laverick says the business still feels as new and bleeding age as it did at the beginning.
A nice addition to vSphere4 and the vCenter 4.0 tools is a change to the vCenter DB retention policy. Before, the vCenter database grew day-by-day and week-by-week. There was no way to limit the size and set a point to start a First In First Out process to overwrite the oldest information with the newest. In vCenter 4.0, the vCenter Server Settings offer a retention policy time. Perhaps the vendors "borrowed" this idea from users, or on their own, but at least the vendors are expanding capabilities regularly. And with books like VMware vSphere 4 Implementation, you can expand your virtual capabilities.