HP gooses Integrity server virt with PA-RISC emulation

Hewlett-Packard is getting serious about getting customers to move off those vintage HP 9000 boxes, based on its final generation of home-grown PA-RISC processors, and onto shiny new Itanium-based Integrity blade servers.

With the launch of HP-UX 11i v3 Update 7 today, HP's flagship operating system will be able to run compiled PA-RISC applications inside of partitions equipped with an emulator.

That emulator, called Aries and technically a dynamic binary translation layer that converts PA-RISC calls to Itanium calls, has been around since the early days of the Itanium chip, which was co-developed by HP and Intel. The Itanium was intended to storm the world, knocking out all other processors (including the x86, Sparc, Power, and MIPS). But thanks to Intel's ineptitude with Itanium, Advanced Micro Devices' genius (and perhaps luck) in getting the Opteron x64 processors out exactly when Intel was weakest in 2003, and Intel's cloning of the Opterons with its Core-based Xeon servers, the Itanium has now been relegated to more or less the same position as the PA-RISC chip was at HP: running HP-UX applications, with a smattering of OpenVMS, Windows, Linux and NonStop clusters.

According to Katie Curtin-Mestre, director of software planning and marketing for the HP Business Critical Systems division (which makes and sells Integrity iron and tries to herd the old HP 9000 and AlphaServer shops toward modernity), the Integrity machines' secure resource partitions have been extended to support the Aries emulator. And now customers can take an HP 9000 server's applications, virtualize them, and plunk them into HP 9000 containers with the Aries emulator pretending to be the old iron.

Customers are understandably hesitant when it comes to emulation, with the initial Aries emulators imposing a heavy performance penalty on CPU-intensive workloads. But most commercial applications running on HP-UX are I/O bound, and the performance penalty was something more on the order of 25 to 50 per cent, according to posts in the HP forum from four years ago.

In the latest Aries benchmark tests, HP pitted an rx2600 using the two-core 1.67 GHz Itanium 9100 processors running the Aries emulator against three machines running a suite of applications in native mode on various releases of HP-UX 11i. The benchmark suite included a mix of the SPECint2000, SPECfp2000, SPECjvm98, and SPECjbb2000 tests from the Systems Performance Evaluation Corp as well as the open source SysBench test suite. The latter is an old MySQL database benchmark that has not been updated for many years; HP used SysBench v0.4.8.

The test suite was run on an rp5450 with four 440 MHz PA-8500 cores, and using the Aries emulator, the Itanium system was able to do about twice as much work with the same number of cores (running at nearly four times the clock speed). The Integrity rx2600 machine with two Itanium 9100s was able to handle about 25 per cent more work running the benchmark suite than an rp5470 with four PA-8700 processors running at 750 MHz. Not surprisingly, the Integrity rx2600 machine was able to crank through about 25 per cent less work than an rp440 machine with two dual-core PA-8900 processors spinning at 1 GHz.

HP has not put out more recent benchmark tests for Aries running on the new Integrity servers based on the quad-core "Tukwila" Itaniums, which made their debut in February and which appeared in a line of Integrity blade servers back in late April. HP is supporting three of the five Tukwilas in its blades - the 1.33 GHz Itanium 9320 (155 watts), the 1.6 GHz Itanium 9340 (185 watts), and the 1.73 GHz Itanium 9350 (185 watts) - and based on clock speed alone you would not expect much of a performance boost, core for core, compared to the Itanium 9100 chips running Aries.

However, the QuickPath Interconnect memory and I/O interconnect, larger cache memory on chip, and hyperthreading in the Itanium 9300 processors could provide a significant boost for Aries emulated workloads. At the very least, Tukwila-based blades offer twice as many cores per socket, so workloads could scale using symmetric multiprocessing, overcoming some of the overhead of emulation. If Aries has been tweaked to use HyperThreading and if the faster memory helps, it is quite possible that Aries can draw even or slightly beat a PA-8900 system, core for core.

Curtin-Mestre says that HP 9000 containers running on Integrity iron can support any PA-RISC workload that has been compiled to work with HP-UX 11i v1, v2, or v3; both 32-bit and 64-bit PA-RISC applications are supported on the emulation layer. The Aries emulator, which you can find out lots about here, is used in production by an undisclosed number of customers.

For a while, the emulation software could only work on native PA-RISC applications, but in March 2008 Aries was updated to allow for mixed-mode operation between emulated HP 9000 applications and native Integrity applications. So, for instance, you could have an HP 9000 Java application call a Java Virtual Machine running natively on the Integrity iron instead of an emulated JVM running inside Aries and originally tuned for PA-RISC iron. (This feature is called MITR, short for mixed-mode translator. Yes, I know MMT was a better acronym.) While the old HP-UX 10.2 and 11.0 releases for PA-RISC machines are not technically supported on Aries, Curtin-Mestre says that there are indeed customers who are doing so.

HP is allowing customers to transfer existing HP-UX 11i licenses from HP 9000 boxes over to Integrity machines and their HP 9000 containers for free so long as they are on current maintenance and support contracts. HP 9000 containers and the Aries emulator are supported as features of HP-UX itself, so you are not using some unsupported product if you adopt them.