PowerVM: The i Hypervisor Is Not Hidden Anymore
April 30, 2008 Timothy Prickett Morgan
If you want to blame someone, go ahead and blame people like me. Or, if it makes you feel any better, just blame me alone. For years, while I have praised the integrated nature of the AS/400 and its progeny, I have railed against the practice that IBM has had of bundling most of its software features on the platform and lumping it all together with a big, fat, single, hardware-software price tag that would give the wealthiest SMB shop a big sticker shock. Perhaps big enough to scare them off, even if a complete Windows stack cost the same or more.
To that end, myself and others who see this problem have been asking IBM until we were, well, blue in the face, to keep all the integration, but to break out the OS/400 and i5/OS components as features, move some elements to user-based pricing, and to basically create a stack that more closely resembles, in price and packaging, what Microsoft offers with its Windows Server System, which is the high falutin’ name Microsoft gives to Windows Server and all of its middleware components, SQL Server database, and Exchange Server groupware.
While the former System i division didn’t listen all that much to these complaints, the System p division, which was trying to sell against other Unixes and Windows boxes, certainly did listen. The AIX platform has been modularized for years, which to be fair is easier since it does not have an integrated database management system. And for a number of years, one of the items that has had a separate set of feature codes and prices on AIX boxes is the Virtualization Engine hypervisor, which the AIX folks called Advanced Power Virtualization, or APV for short, and which they delivered in a number of different editions. With the Power Systems convergence that was announced in April, the hypervisor and its related tools were rebranded as PowerVM and the pricing and packaging that was previously used only on the System p servers were adopted for the Power Systems i Editions. Up until now, IBM has bundled the cost of the PowerVM hypervisor and its related tools for partitioning and managing logical partitions into the cost of the server themselves. This meant, in effect, that AS/400, iSeries, and System i customers who were not partitioning were subsidizing those who were. Now, it is all out in the open, with gradually increasing functionality having a gradually rising price.
The PowerVM software stack comes in three flavors: Express, Standard, and Enterprise Edition. All three editions have the basic hypervisor for virtualizing the underlying Power server iron and allowing multiple and, if need be, incompatible i5/OS, i, AIX, and Linux operating systems to run side by side on a single physical machine. All three editions also have a number of features that are, for now at least, being provided for free (meaning bundled in terms of pricing) with the PowerVM hypverisors, but some functionality is only available in certain editions. The basic idea that IBM wants is to have three different price bands for server virtualization on all Power platforms, and then to add functionality as it sees fit for those price points.
PowerVM Express is the inexpensive version of the product (and was given away free on some servers, such as JS21 blades), and it comes by default with all new Power Systems machines (and prior System p boxes and JS22 blade servers). This edition of the hypervisor can provision up to three partitions on a single server (not core) and uses the Integrated Virtualization Manager (IVM) console to create and manage these partitions. PowerVM Express is available on Power 520 and Power 550 machines as well as on the JS12 and JS22 blade servers. In addition to the hypervisor, which can provision i5/OS V5R4, i 6.1, AIX 5.3, AIX 6.1, and Linux 2.6 partitions, the PowerVM Express Edition also includes the Virtual I/O Server (VIOS) disk and networking virtualization appliance that was created for the AIX and Linux operating systems to simplify how peripherals were supported in these machines in conjunction with the PowerVM hypervisor. (You will recall that JS12 and JS22 Power6-based blade servers using i5/OS V5R4M5 or i 6.1 require VIOS to talk to disks and network ports in the BladeCenter chassis because IBM did not want to go through the trouble of writing native i5/OS V5R4 and i 6.1 drivers.) The base hypervisor allows for micropartitioning (putting more than one partition on a single processor core) and allows for a single partition to span multiple cores as well, if that is what customers want to do. Starting with AIX 6.1 and i 6.1, the basic hypervisor also includes the PowerVM Lx86 runtime environment, a variant of the QuickTransit emulation software from Transitive that allows Linux applications compiled for 32-bit X86 chips to run unmodified on Power5, Power5+, and Power6 servers. PowerVM Express Edition costs $30 per core, plus $10 per year for Software Maintenance.
Moving up a notch is PowerVM Standard Edition. This has all the same functionality as the Express Edition, but can create and manage up to 10 logical partitions per processor core and can be managed by either the Integrated Virtualization Manager (IVM) or a Hardware Management Console (HCM). The HCM software is required for i5/OS, i, and AIX machines with more than one partition running those operating systems, but the IVM tool can be used to manage Linux partitions up to a certain point. PowerVM Standard Edition runs across the prior System p line and on the new Power Systems line. On Power6-based machines, this edition also has two other capabilities: multiple shared processor pools and shared dedicated processors. The former capability allows system administrators to group a bunch of micropartitions together and share resources dynamically amongst themselves so long as they do not go beyond a capacity limit set for the pool; the latter allows unused capacity in micropartitions or groups of them that have been put together into pools to be accessed by other partitions in the machine on a dynamic basis. It is not clear if these functions are going to be enabled in i 6.1, but they are in AIX 6.1 and Linux 2.6.
PowerVM Standard Edition has another thing: A price. In fact, it has two prices: a price for the software and a price for Software Maintenance. IBM charges for it based on the size of the machine–small, medium, or large, plus another category called integrated; I have not been able to identify what machines in the Power Systems family fall into what class yet. On a small system, PowerVM Standard Edition costs $590 per core plus $110 per year for Software Maintenance (that’s for 9×5 business support, and 24×7 support costs $29 a year more); on a midrange machine, it costs $990 per machine plus $110 per year for maintenance; and on a large server it costs $1,280 per core plus $110 per year for maintenance. On the so-called integrated systems, PowerVM Standard Edition costs zero, zip, nadda. (In the past, IBM has given the PowerVM hypervisor away for free on AIX and Linux blade servers to keep them competitive with VMware‘s ESX Server hypervisor running on blades.)
PowerVM Enterprise Edition is the big dog, and on AIX platforms, it includes the Live Partition Mobility functionality that has yet to make its way to the i platform. Live Partition Mobility allows a running logical partition to be moved from one physical Power server to another one so long as they are using shared storage and are connected with respectably fast networking. This feature requires the Power6 processor, but works with AIX 5.3, AIX 6.1, and Linux 2.6. AIX 6.1 also includes Live Application Mobility, which used to be called Workload Partitioning, which allows an AIX application, not a whole partition, to be moved from one machine to another one. This works on Power4, Power5, Power5+, and Power6 servers running AIX 6.1 and using Network File System as the file system. Live Application Mobility is not a function of the hypervisor–at least not yet. But it could very well be pushed down into that layer and thereby supported on i and Linux workloads as well as AIX jobs.
As you might have guessed, PowerVM Enterprise Edition costs more money, since it does that partition migration trick. On a small system, it costs $1,169 per core; on a midrange system, it costs $1,470 per core; and on a large system it costs $1,969 per core. On embedded systems, PowerVM Enterprise Edition costs $309 per core. Software Maintenance for the Enterprise Edition costs $220 per year, regardless of machine class.
Correction: In the original version of this story, we said that the PowerVM Express Edition hypervisor was free. Technically speaking, it is not, although IBM did provide it for free on some machines prior to now. PowerVM Express Edition indeed does have a list price, and it is $30 per core. IT Jungle apologizes for any confusion this may have caused. [Corrected 04/30/08.]