A new server lineup needs a new operating system to match it, and so next month will see the debut of AIX 7.1 from IBM. And about a month earlier than expected, too.
AIX was always the laggard when it came to commercial-grade Unixes, far behind HP-UX from HP and Solaris from Sun Microsystems. And that, along with some pretty pathetic Power-based server iron, meant that HP and Sun controlled the Unix market.
But a decade ago, IBM got its Power server act together at exactly the same time that Intel's Itanium woes started hurting HP, and Sun's hubris screwed up the UltraSparc III server launch. IBM got very respectable dual-core Power4 processors out the door, and started adding capacity-on-demand and virtualization features to AIX — capabilities that that HP and Sun systems already had. Combined with very aggressive price cuts on systems — the starting negotiating price was 50 per cent off, and it went down from there pretty quickly if it was a Sun or HP takeout — the software enhancements made IBM a relatively safe alternative.
The sad irony these days is that you could make an argument that IBM's Power Systems are the only safe Unix bet when what the IT market really needs is three strong players. Oracle will eventually get its Sparc and x64 server act together, and HP will persevere with Itanium for HP-UX.
There is still room for improvement for IBM's AIX, as there is for every operating system, but the big gut-wrenching changes for AIX were put to bed between AIX 5.1 and 6.1. By comparison, AIX 7.1 is a modest upgrade in functionality that uses the same packaging that IBM has been tweaking with the AIX 6.1 release.
AIX and its companion PowerVM hypervisor, which has been upgraded to the 2.2 release along with AIX 7.1, has logical partitioning as well as workload partitions — IBM's Solarisesque riff on the virtual private server theme — for virtualization. IBM has live partition mobility to move running logical partitions (LPARs, in the IBM lingo) from one physical machine to another, and live application mobility to scoot workload partitions (WPARs, of course) around a pool of networked machines.
PowerVM can scale an LPAR from as small as 1/10th of a processor core (called a micro partition) on a Power System all the way across all 256 cores and 1,024 threads in the full-bore Power 795 machine that was announced this week.
LPARs can be allocated and deallocated dynamically, and PowerVM has features to automatically load-balance LPARs and WPARs as need be in a pool of systems. LPARs can be dedicated to specific resources, or thrown into a shared resource pool where their quality-of-service settings compete for resources.
The LPARs can be hooked into power-management features of the Power Systems iron so processor cores, memory, and other components are shut down as they are not needed, corralling LPARs and WPARs on as few physical components as possible, thereby saving energy. The Power Systems machines have hot-add and hot-remove processor, memory, and I/O with the AIX operating system running, and AIX 6.1-included memory compression as well.
All of these features took the better part of a decade for IBM to add to AIX, and were absolutely necessary for AIX to be a modern operating system. Many of these features were nicked from IBM's proprietary OS/400 operating system, but the Unix people in IBM's Austin, Texas, development lab will never cop to it — just like they'll never really admit that it was the AS/400's Rochester, Minnesota, lab that created the first several generations of the 64-bit Power chips that made it possible for Big Blue to not be an also-ran in the Unix business.
And those wickedly high prices IBM charged for AS/400 and iSeries hardware and software in the late 1990s and early 2000s are precisely what allowed IBM to sell RS/6000 and pSeries hardware at 50 per cent or less of list price and not go broke. IBM screwed one customer base to acquire another — and while that strategy worked as far as quarterly results go, it's kind of stupid when you consider that AS/400 shops were IBM's most loyal customers and about half of its enterprise customer base.
But back to AIX 7.1. Its most important feature is that it is binary compatible with AIX 5.X and 6.1, which means that Power Systems shops do not have to recompile their applications to run them atop AIX 7.1. The latest IBM Unix runs on any machine that uses the dual-core PowerPC 970, Power4, Power4+, Power5, Power5+, Power6, Power6+, or Power7 processors. IBM currently still supports AIX 5.3, which dates from 2005's Power5 generation and which included the Virtual I/O Server and micro-partitioning for AIX for the first time. According to Jeff Howard, director of marketing for IBM's Power Systems division, IBM will continue to support AIX 5.3 until early next year, and indeed, that vintage operating system is supported on current Power7-based machines.
But AIX 5.2 is not, and this is a problem, since it's still out there in pretty large numbers in the RS/6000, pSeries, and System p installed base. So with AIX 7.1, IBM has tweaked its WPAR virtual private servers so they can take a backed up instance of AIX 5.2 and its applications and suck it into a WPAR and run it unchanged.
WPARs use a single, shared AIX kernel and file system across virtual machines instead of logically isolating whole AIX instances inside of partitions to create virtual machines, and this is exactly the kind of thing to which they are well-suited — and moving to new hardware while not changing software is something customers love to do. Howard won't say if a future release of AIX 7 will support AIX 5.3 WPARs, but obviously it will unless IBM has lost its mind.
The AIX 5.2 WPAR support on AIX 7.1 has some limits. IBM's PowerHA clustering cannot span multiple WPARs and cluster them, and IBM's workload-management tools don't work in managing these AIX 5.2 WPAR instances as they did on the real AIX 5.2 machines. For some reason, the NFS file system is also not supported within the AIX 5.2 WPAR; the JFS2 file system is. There are limits to the mobility of the AIX 5.2 WPAR as well.
The AIX 5.2 WPAR feature for AIX 7 carries an additional fee atop of the per-core AIX fees. It costs $60 per core on small Power machines, $170 per core on medium machines, and $310 per core on large machines. If you want the AIX 5.2 WPARs to be mobile, you have to buy PowerVM Workload Partitions Manager for the AIX 7.1 Express or Standard Edition, or get AIX 7.1 Enterprise Edition, which includes this tool as part of its bundle.
Cranked-up core coverage
The other important change with AIX 7.1 is important for those high-end machines — the Power 770, 780, and 795 — which have lots of cores and threads: more core headroom.
The Power7 chip has eight cores and four threads per core, but AIX 5.3 and 6.1 topped out at supporting 64 cores and 128 threads, which is what the Power6-based Power 595 scaled to. AIX 6.1 was tweaked with patches so it could support 64 cores and 256 threads, which is what the Power 770 and 780 scale to, but AIX 6.1 is not being extended to run across the whole Power 795, with its 256 cores and 1,024 threads. If you want to run across an entire Power 795 as a single system image — or even break it into two 128-core, 512-thread machines — you have to move to AIX 7.1.
Other changes with AIX 7.1 include support for solid state disks in the AIX logical volume manager and JFS2 file system; terabyte-segment memory support for main memory; and built-in clustering for AIX 7.1 Standard and Enterprise Editions that is, in essence, a subset of the PowerHA SystemMirror clustering software embedded in the operating system. (IBM did a similar thing with OS/400 V4R4 back in 1998, just to show you how old the idea is. IBM chose code from HA partner Vision Solutions to embed in OS/400, and for AIX is using its own PowerHA code, formerly known as HACMP.)
AIX 7.1 Express Edition is the lowest-priced version of IBM's Unix, and it is intended to run on machines with four or fewer cores or within logical partitions with four or fewer cores; the machines or partitions top out at 8GB of main memory. The idea is to provide a cheap, basic AIX for infrastructure and application workloads. AIX 7.1 Express costs $300 per core on a small Power machine, $800 per core on a medium machine, and $1,500 per core on a large machine.
AIX 7.1 Standard Edition has no limits on how many cores or how much main memory it can span, and as such, it has a higher price. On a small machine, it costs $500 per core, while on a medium box it runs $1,400 per core and on a large box it costs $2,600 per core.
AIX 7.1 Enterprise Edition throws in extra goodies such as PowerVM Workload Partitions Manager (mentioned above), Systems Director Enterprise Edition (which has all of IBM's systems, virtualization, and power management smarts), Tivoli Monitoring, and Tivoli Application Dependency Discovery Manager. AIX 7.1 Enterprise Edition costs $790 per core on small boxes, $2,126 per core on medium boxes, and $4,052 per core on large boxes.
That's $1.03m for the top-end AIX 7.1 at list price on a Power 795 with all of its cores turned on and running AIX — even at 50 per cent off. And that's big money for relatively little work, and also explains, perhaps better than anything else, why Oracle bought Sun Microsystems.
PowerVM 2.2, which ships on September 10 along with AIX 7.1 and which supports IBM's I 6.1, 6.1.1, and 7.1 proprietary operating systems as well as Linuxes from Red Hat and Novell, can support as many as 80 LPARs on the new Power 710 and 720 servers, and 160 on Power 730, 740, 750, 770, and 780 boxes. The Power 795 currently tops out at 254 partitions (not 256 as you might expect). Sometime in 2011, IBM will boost the supported number of LPARs on the Power 770 and 780 to 640 and on the Power 795 to 1,000 (not 1,024 as you might expect).
AIX 7.1 has been in a public beta since mid-July, and this is only the second time in the 20 years IBM has been in the Unix racket that it did a public beta. More than 1,100 customers have downloaded the code and signed up to participate in the beta program, which ends in October. ®