Edit: Most everyone virtualizes these days, although I still know of vendors that prefer you run one big LPAR per frame.
Originally posted November 30, 2010 on AIXchange
Working on virtualized systems as much as I do, and talking to people about virtualization as often as I do, I tend to forget a couple things:
- Not all IBM Power Systems users have virtualized systems.
- Not all of them use VIOS even while they benefit from other aspects of virtualizing their machines.
It isn’t necessarily that these shops are limited by the constraints of older hardware and operating systems. I know of customers with POWER6 and POWER7 hardware that haven’t yet virtualized their systems. Maybe they lack the time or the resources to virtualize more fully, or maybe they simply lack the skills that come only with hands-on experience.
Customers who aren’t hands-on generally don’t realize that virtualization covers a wide range of functionality. Using workload partitions (WPAR) counts as virtualization. Micropartitioning CPU, where we assign fractions of a CPU to an LPAR and then set up processing entitlements and cap or uncap partitions based on our LPAR’s requirements? That’s virtualization. We use VIOS to virtualize disk, the network or both. NPIV allows us to virtualize our fibre adapters and have our clients recognize the LUNs we provision–and it saves us the effort of having to map them to the VIOS and remap them to the VIOS client LPARs. We use the built-in LHEA to virtualize the network. We could create an LPAR with some dedicated physical adapters and some virtual adapters. We could use active memory sharing and active memory expansion to better utilize our systems’ memory. Power Systems offers many choices and scenarios where it can be said that we’re using virtualized machines.
I know some administrators who’ve been unable to convince their management or application vendors of virtualization’s benefits. I know of some IBM i users who are reluctant to get on board with VIOS (though plenty of AIX shops still don’t virtualize, either). Sometimes it’s the vendor that lacks the time, resources or skills for virtualization. For instance, I’ve seen multiple customer sites where tons of I/O drawers are used; the vendor won’t officially support VIOS because the vendor hasn’t tested it, and these customers don’t want to run an unsupported configuration.
I talked to an admin who has experience with configuring logical partitions, setting up dedicated CPUs and dedicated I/O slots in his environment, but he continues to use a dynamic logical partition (DLPAR) operation to move a physical DVD between his different LPARs. It’s the way he’s always done it. He figures that since his shop doesn’t use virtualization is no big deal, since he has no experience with VIOS and virtual optical media anyway. “You can’t miss what you’ve never had,” is how he put it.
Others will tell me that they the see the writing on the wall. They insist they’ll virtualize, some day.
Are there roadblocks keeping you from virtualizing? Are there complications that prevent you from moving to a fully virtualized environment? I’d like to hear about the challenges you face. Please e-mail me or post in Comments.