Edit: I still say LPAR all the time. Nigel’s link no longer works. People still fight over AS/400 and IBM i.
Originally posted May 24, 2011 on AIXchange
In an AIXchange blog entry last month, when I discussed the new SDMC IBM Redbook, I noted that:
“Section 1.5 shows us how the terminology will evolve. Managed systems are now called servers, frames are power units, LPARs are virtual servers, the hscroot ID becomes the sysadmin ID, partition mobility becomes relocation, etc.”
Nigel Griffiths took this a step further, recently arguing that the time has come to call our partitions virtual servers or virtual machines rather than LPARs:
“So the observant might have noticed a sharp decline in the term LPAR in the last three or four months. Apparently … this change is now recommended within IBM and IBM marketing, so you will see a lot more use of the new terms. This is a change in name that I whole heartedly approve- unlike, for example, RS/6000 to pSeries to System p to Power Systems (which now confuses the world’s fastest general purpose computers with mains electricity power supplies!). Of course, ‘LPAR’ will turn up out of habit on the Internet, in documents and articles for many years to come and be popular with IT luddites now that it is old fashioned. …
“When I think back to it, the Logical Partition (LPAR) name never did make much sense!
“Logical: means shared or pretend or not physical.
“Partition: means a part of the whole and started life as a disk term as a group of sectors.”
Like Nigel, I guess I never gave much thought to the terms “LPAR” and “logical partitions.” I was used to them. In my head I always compared LPAR with a hard or dedicated partition or a standalone server. The dedicated partition would have some sort of dedicated hardware–dedicated processors or dedicated adapters. A logical partition was fully virtualized using virtual or logical devices, disks, network, shared processors, etc. To me it made sense to call it a logical partition since it was using logical devices. Because dedicated and logical partitions could be mixed and matched on a physical frame, I appreciated that this terminology easily differentiated the kind of LPAR we were talking about.
Virtual systems and virtual machines are appropriate terms for this updated technology. But with VM’s history, there is potential for confusion. There’s not only VM, the old mainframe operating system, but there’s VMware, the non-IBM virtualization software. PowerVM is obviously far more powerful than VMware, but again, they have that VM term in common.
I’ll certainly try to call them VMs going forward, but don’t be surprised if I occasionally make reference to LPARs. And I’m sure I won’t be the only one–after all, plenty of customers still tell me about their AS/400 and RS/6000 systems, even though they’ve been on POWER7 servers for some time. Despite the new direction in terminology, I wouldn’t be surprised if we continue to hear about LPAR well into the future.
All that matters really is that everyone understands what we’re talking about. Perhaps going forward we’ll find a way to differentiate a VM with dedicated adapters versus a fully virtualized VM. Or does that distinction even matter anymore? How quickly do you expect your vocabulary to change?