IBM i Added To Power S822, PurePower Systems
October 12, 2015 Timothy Prickett Morgan
Since the entry Power8 machines launched early last year, we have been arguing that Big Blue needs to offer IBM i on a larger span of the Power Systems machines it has in the portfolio. Customers should be able to device which is the best box for them, just like Linux and AIX shops, rather than have IBM decide that for them ahead of time. IBM’s desire to help managed service providers build denser and cheaper clusters seems to be playing into the favor of IBM i shops that want to run their own machines.
This is a good side effect.
To be precise, IBM will be supporting IBM i 7.2 Technology Refresh 3 and IBM i 7.1 Technology Refresh 11 on the Power S822 server, a machine that thus far has only supported AIX or big-endian Linux. (The existing Power Systems L and now the new Power Systems LC machines, also announced last week, support little-endian Linux but not AIX or IBM i.) These TR updates for the two current versions of IBM i will be available on November 20, and at that time customers who move to the 840 level of firmware will be able to run IBM on top of this machine. Thus far, IBM has only supported IBM i on the single-socket Power S814 and the two-socket (and much fatter in terms of chassis size and peripheral expansion) Power S824 machine.
The Power S822 is a two-socket machine as well, but one that has a 2U chassis like the Power S814 and considerably denser than the 4U chassis of the Power S824. It has two processor cards, each with one Power8 chip and 512 GB of main memory, for a total of 1 TB across the system. There are two processor options for this machine: a six-core chip running at 3.89 GHz and a 10-core chip running at 3.42 GHz. This Power S822 has six PCI-Express 3.0 slots with the base processor card and another three more come with the second processor card. The 2U chassis has room for eight 2.5-inch drives plus another six 1.8-inch units and you can add even storage with up to 14 of IBM’s EXP24 storage expansion drawers.
The size of the box doesn’t always matter to customers, unless they are trying to cram a lot of machines into a confined space, like many cloud builders are. So for many shops, physically speaking the size of the Power S824 is not a big deal. What was, and continues to be, a big deal is the fact that the Power S824 machine is in the P20 software tier for IBM i, which makes its license considerably more expensive than the P05 software tier of the Power S814 with four-cores and the P10 tier with more than four cores. For customers who want to cram more compute into a smaller space–again, think service providers–or those who have many logical partitions that need a certain amount of compute, the Power S824 was too expensive when it came to software and the Power S814 didn’t have enough cores or memory capacity. Here’s what the two machines look like:
Supporting IBM i on the Power S822 is a good compromise. Rather than just let customers go nuts, however, IBM is putting some caveats on the IBM i software running on the Power S822 machine. First, all of the I/O for the IBM i operating system running on the Power S822 has to be virtualized using the Virtual I/O Server (VIOS), which is not exactly the favorite piece of software at many IBM i shops. VIOS is a baby AIX server that has to be managed differently, and it imposes overhead on I/O compared to native access to peripherals. What this means is that you cannot support cryptographic accelerators or asynchronous/bisynchronous I/O adapter cards, which only work natively on IBM i. IBM also warns that disk drives and flash SSD drives used inside the Power S824 chassis or in the EXP24 I/O expansion drawers have to have 4 KB sector formatting instead of legacy AIX 512 B or OS/400 524 B formatting. (Byte looks really funny without a Greek prefix.) IBM says that this 4 KB sector size is required for performance reasons.
The other caveat is that IBM is artificially setting the logical partition size on the Power S822 to a maximum of two cores. The reason was not made clear, but the intent seems obvious enough to me. If IBM puts out a P10 machine that can have 12 or 20 cores, customers might buy this instead of a Power S824, which costs more, or a Power E850, which costs a lot more. Both are in the P20 tier. The Power E850 can have up to 48 cores running at 3.02 GHz (or 40 cores at 3.35 GHz or 32 cores at 3.72 GHz) in a 4U enclosure, so it wins the density game, and it delivers 2 TB across four processor cards. But the higher price on the Power E850 hardware and paying that P20 software tier across those cores makes it unattractive compared to the Power S814 with eight cores. Supporting IBM i on the Power S822 shoots the gap between the two, striking a balance between density, core count, and license price.
This also fulfills IBM’s promise to deliver IBM i on its PurePower pre-configured server clusters, which are aimed precisely at the service provider customers who buy machines by the rack, not by the node. We told you all about the PurePower converged systems back in June, which stack and rack Power S822 and S822L machines with AIX or Linux, respectively. The PurePowers also include Storwize V7000 arrays (with flash and disk) and integrated storage virtualization, and use IBM’s variants of KVM and OpenStack for Power to virtualize and manage the compute. It is not clear how IBM i is managed by OpenStack and how other tools in the stack, such as PowerVC and Nagios, come into play.
The PurePower machines are intended to replace IBM’s former Flex System modular machines, which were sold off to Lenovo Group in October 2014. IBM has come up with a migration plan and incentives to move customers from Flex System to PurePower clusters, which we told you about here. While IBM technically was making Power nodes for the Flex Systems, they did not exactly sell like wildfire. Most IBM i shops want fairly beefy rack machines and most service providers want dense rack gear, not blade or modular systems.
The point is, customers or service providers can now run IBM i 7.1 TR11 and IBM i 7.2 TR3 on the nodes in the PurePower machines, with all the stipulations and limitations outlined above.
Whether in the plain vanilla Power S822 or the PurePower clusters based on them, running IBM i on the Power S822 requires for the VIOS to be at the 126.96.36.199 release level and the microcode firmware of the system to be at the 840 level. These machines are orderable with IBM as of October 5 and the updated software ships on November 20.
I have not forgotten that IBM announced the new lower-cost, Linux-only Power Systems LC machines last week. But these machines do not support IBM i, so there is not much else to say other than what I have already said, and that is that I think that they should. You can read my initial analysis of these machines over at The Platform at this link.