Mainframe Storage

All Nines: The DS8900F — Now Generally Available

By Archive User posted Tue November 26, 2019 10:45 AM


Originally posted by: Kimmel






On 12 September we've announced the ninth and latest generation of DS8000, the IBM DS8900F, running on the R9.0 version of microcode.

DS8900F is an all-flash storage system, based on POWER9 processor complexes, and the 2nd-generation High-Performance Flash Enclosures for the drive backend.

Compared to DS8880, we have reduced the number of models. While DS8880 was available in both hybrid (HDD+flash) 283x versions as well as all-flash 533x model versions, and then with several submodel options for single-phase power and three-phase power attachment, the DS8900F just comes as either the DS8950F, or the DS8910F. And for the DS8910F, we have two submodel options: The 993 "rack-mounted", which can be installed in any customer-provided rack, or installed within the same frame like a z14 ZR1 Business Class or LinuxONE LR1, together with the host. Or there is the DS8910F submodel 994 racked model, which brings its own rack.

All models can be either three-phase power, or single-phase power attached.

The large model DS8950F 996 comes with a possible E96 Expansion frame. All models are only 40U high, unlike the DS8880, which partially had heights up to 46U for some models.

The DS8910F "Flexibility Class" is the successor for both the DS8882F, as well the DS8884 and DS8884F models. Given that it can have cache sizes of 192 GB or 512 GB, so doubling the max. cache size of a DS8884, and given the much stronger POWER9 processing capability (per core from 4.2 bn to 8 bn processors, compared to POWER8), and the dual 8-core configuration compared to a dual 6-core POWER8 of the DS8884, the scope for which this model is intended for is much wider than for the previous DS8884 Business Class. Even the smallest 993 model comes with the zHyperLink attachment option now.

The DS8950F "Agility Class" is the successor for the models DS8886F, DS8886 and DS8888F. It offers the biggest scaling in terms of cache and of processing power, with a system memory size up to 2 TB and a maximum of dual 20-core POWER9 processor complexes. The max. NVS write cache size has doubled compared to the biggest DS8888F model.

The new POWER processor generation offers not only up to a 60% increase in the possible maximum I/Os per second for a respective model — the improved processing power also helps to reduce latency by typically a further 9%.

The DS8900F comes with the superior and proven RAS capabilities of the Power server architecture and achieves a seven-Nines availability. Using zHyperLink, record-low response times around 18 µs are possible, for Z hosts like IBM z14 and higher.

The DS8900F inherits advanced functions like for Copy Services, or the patented cache algorithms, or like Transparent Cloud Tiering from its DS8880 predecessor. Cyber resilience functions like Safeguarded Copy, which currently are adopted by many clients especially from the financial sector, are also available in all new models.

A bigger architectural change comes with the way we handle the write cache when both power cords would go away. Instead of the huge DC-UPS elements we had in earlier models, which combined the AC-DC power conversion with a longer-term battery hold-up to let the processor complexes move all data down to disks, we've gone to a NVDIMM architecture now instead, which allows to process this function in a lot shorter timescale and using very compact parts. Data is locally encrypted in the NVDIMMs, and the smaller components also allow to reduce the footprint (depth) of the DS8900F further, compared to DS8880. The rack power control is now done by new ethernet-managed Intelligent Power Distribution Units (iPDU).

Another big change is the new 32 GFC fibre adapter. Not only that it comes with a doubled per-port speed. Clients have asked us to provide encryption of data in flight, and the new adapters in the DS8900F offer Endpoint Security, which is the choice to either authenticate the ports in the SAN with a trusted certificate, or even to fully encrypt the I/O data traffic while on SAN, and not using up host CPU cycles for this. The IBM z15 is so far the only host which can use this new Endpoint Security option.

The DS8900F also comes with a new look and feel for its Graphical User Interface (GUI), which further unifies the experience across all other recent IBM storage systems. The picture at the bottom gives an impression of the new GUI, showing the management of Endpoint Security at a certain fibre channel port.
Remote Code Load is a standard option.

The Smart Rebuild function is now available with flash drives in RAID-6, within the High-Performance Flash Enclosures. Easy Tier remains to be a free feature, and with the High-Capacity Flash options that we have in the flash drive portfolio, we can build cost-optimised mixes of high-performance and high-capacity flash which can replace legacy multi-frame installations yet with a very short response time, and much lower energy consumption. Flash Tier 2 options like the 15.68 TB drives, or the economic 1.92 TB Flash Tier 2 in the DS8910F, can be used as add-ons to provide very small footprints.


Several IBM Redbooks publications around DS8900F have been written at ESCC Kelsterbach by an international team of authors, and the first ones are already available, as draft versions:   


Find more information in the IBM Knowledge Center for DS8900

or the DS8900F Introduction and Planning Guide