Inside IBM’s SAP HANA On Power Playbook
May 21, 2018 Timothy Prickett Morgan
The Power Systems line is in transition right now, making the jump from Power8 to Power9 processors, and yet the company wants to continue selling applications without having customers wait for the newer chip to be available across the entire Power Systems portfolio. This is a particular problem when it comes to the HANA in-memory database on Power Systems, which IBM is eager to sell given the higher memory capacity and bandwidth that Power9 offers compared to the Xeon processors from Intel.
To help business partners that are peddling SAP suites on Power, which includes the IBM i platform, in conjunction with or side-by-side with the HANA in-memory system, the offering managers behind the application stack have put together a playbook to help everyone get on the same page.
In the first quarter just ended, the advice from IBM was to do proofs of concept with HANA on Power9 gear if it was available and then move into production on Power8 for those who could not wait. HANA certification on Power9 was not expected until the second quarter (which is now). Once this HANA certification is available on Power9, then customers have to consider the memory capacity they need on their HANA nodes. With the Power8 chips, thanks to the buffered “Centaur” memory, the capacity per socket tops out at 4 TB, compared to 2 TB per socket for the Power9 for the scale-out versions of the machines – these would be the “ZZ” and “Boston” machines we have discussed here in The Four Hundred. This is still better than the 1.5 TB per socket cap on the “Skylake” Xeon SP Platinum processors from Intel. IBM says that it has tuned up HANA atop its PowerVM hypervisor to work well, and that there are some restrictions (these are not detailed) when running VMware’s ESXi hypervisor on top of X86 chips. IBM also says that it will be able to demonstrate better performance per machine on Power9 versus the Xeons as well as the ability to house 33 percent larger databases. There is some interest in even the new ZZ systems because, depending on the quarter, somewhere between 65 percent and 75 percent of SAP HANA licenses are being sold onto machines with under 6 TB of main memory.
For those who need the most memory on a modest machine with one or two sockets, then the advice is to get a Power8 box. For those who can get by on 2 TB per node, then the new Power H922 and Power H924 models, which have special discounts available to offer lower prices than regular Power S922 and Power S924 models (which we have not seen yet, by the way). But these machines can only have 25 percent or less of their core capacity activated to run IBM i or AIX workloads. If customers need to have more IBM i or AIX capacity than this, then they are being told to buy plain vanilla Power S922 or Power S924 machines.
Starting in the second half – and we have heard specifically in the third quarter – IBM will roll out the “Zeppelin” Power E950 (four sockets) and “Fleetwood” Power E980 (eight sockets and 16 sockets) enterprise-class machines, which will offer 4 TB per socket maximum and which will apparently also come in H models with special pricing and configuration for HANA. On these machines, the Elastic Computing On Demand (ECOD) functions of their chipsets will allow IBM i, AIX, and Linux to be configured on the fly on cores, and there is no 25 percent CPW capacity limit for IBM i and AIX on the boxes. The word on the street is that the H models will have “more aggressive pricing and configurations,” and that may mean some customers buy them for SAP HANA, but onload a lot of AIX and IBM i jobs on to the machines, too. But watch it. IBM wants to prevent this and ill have mechanisms to tie discounted capacity to SAP HANA and not free it up for IBM i or AIX.
Up until now, SAP HANA is certified to run atop Red Hat Enterprise Linux and SUSE Linux Enterprise Server, but we hear that with SLES 12 SP3, this operating system will have special functions to take full advantage of Power9 chips, which presumably means RHEL 7.4 doesn’t have it as yet.