IBM touts super-fast storage array for z15 mainframe

IBM launched its latest z15 mainframe today and gave it a new high-end all-flash array to play with. This is the DS8900F and it holds more data with doubled Fibre Channel access speed compared with its predecessor, the hybrid flash/disk DS8880.

Sales of the DS8900F will be closely tied to those of the z15 as a new mainframe refresh cycle starts, just over two years after the z14 generation was launched.

There are two DS8900F models, the entry-level DS8910F and larger and faster DS8950F. The DS8950F has seven nines availability, in common with the DS8880. and is intended to consolidate all mission-critical workloads for IBM Z, LinuxONE, Power Systems and distributed environments.

The upgrade is intended to keep IBM mainframe customers happily connecting DS8000 series arrays to their mainframes and keep Dell EMC. HPE and Infinidat out of this customer base. As well as all-flash technology, the storage array offers faster-than NVMe-oF access speed, cloud tiering, more secure data and AI-powered array monitoring delivered as a cloud service.

Speeds and feeds

The main point of contrast for the DS8900F is with the DS8880, which it replaces. This uses POWER8 CPUs in its controllers and has a maximum capacity of 4,608TB, made up from disk drives and SSDs allied to 614TB of flash cards. 

Mainframe hosts access the DS8900F array via FICON while other hosts use Fibre Channel.

The DS8900F uses faster POWER9 CPUs and its top capacity is 5.9PB, almost 30- per cent more than the DS8880. The supported drive list runs from 800GB flash cards to 15.36TB – nearly ten times more than the DS8880’s 1.6TB top-end drive. 

The big black DS8900F rack box

An EasyTier facility moves data between higher and lower performance flash drives based on the access frequency. Fibre Channel access is either 16Gbit/s or 32Gbit/s. There is no support for NVMe-over-Fabrics.

IBM is making great play with the DS8900F’s response times, saying it’s down to 18μs with mainframe zHyperLink technology and 90μs minimum without.

The new array delivers 50 per cent reduction in transaction time for Db2 workloads, 60 per cent increase in IOPS and 150 per cent increase in sequential throughput. These figures are compared with un-named arrays in IBM internal tests.

The zHyperLink tech is a point-to-point FICON connection limited to 150m distance. The mainframe-attached link provides up to 10 times lower latency than normal FICON.

Security, cloud tiering and AI insights

The DS8900F offers IBM Safeguarded Copy – hidden copies of data that provide immutable points of data recovery and are protected from modification or deletion due to user errors, malicious destruction, or ransomware attacks.

The array can shunt older data to IBM’s Cloud Object Storage,  IBM Cloud, Amazon S3 and an IBM TS7700 tape system configured as an object storage target. This Transparent Cloud Tiering  (TCF) is neat, incorporating Hierarchical Storage Management within the array. There is no need for additional hardware or software, such as SpectraLogic’s StorCycle.

Through integration with the mainframe z/OS, TCT provides up to 50 per cent savings in mainframe CPU utilisation when migrating large datasets, compared to other traditional archiving methods. That’s based on an internal IBM comparison using an EC12 mainframe.

As every mainstream storage array supplier is now doing, IBM is also giving the DS8900F a cloud-delivered and AI-powered system monitoring and support facility, which it calls Storage Insights.

This monitors health, capacity and performance and provides proactive best practices and uses AI-based analytics to identify potential issues.  Storage Insights simplifies opening tickets, automating log uploads to IBM, and providing configuration, capacity and performance information to IBM technicians.


The main competition for IBM’s new storage box will come from Dell EMC, Hitachi Vantara and Infinidat, aiming to sell to IBM accounts which have X86 and Power servers as well as mainframes.

The DS8900F integrates with z15 and LinuxONE mainframe systems and so will compete with Dell EMC’s PowerMAX ,which also supports FICON connectivity.

PowerMax delivers sub-200μs latency with NVMe flash SSDs but the DS8900F with zHyperLink offers 18μs. PowerMax tops out at 4PB.

Infinidat’s InfiniBox array has latencies of 32μs for reads and 38μs for writes when using NVMe-oF with Remote Direct Memory Access over converged Ethernet (RoCE.) 

The InfiniBox F6300 has a 4PB raw capacity maximum but thus can be boosted to an effective10PB through inline compression and space-efficient snapshots. There is no FICON connectivity for InfiniBox.

Hitachi Vantara’s VSP F1500 supports 34.6PB raw capacity level and offers FICON and Fibre Channel connectivity. Data reduction can boost capacity further.

Check out a DS8900F datasheet here. Apply to IBM for pricing details.