This chapter describes the optional IBM zEnterprise Data Compression (zEDC) Express feature of the Z platform. The information covers the following topics:

The growth of data that needs to be captured, transferred, and stored for long periods of time is unrelenting. Software-implemented compression algorithms are costly in terms of processor resources. Storage costs are not negligible, either.

The optional zEDC Express feature (FC 0420) addresses those requirements by providing hardware-based acceleration for data compression and decompression. When used with IBM z/OS version 2.1, the zEnterprise data compression acceleration capability of the zEDC Express feature reduces processor use, optimizes performance of compression-related tasks, and enables more efficient use of storage resources. This integrated solution also lowers the cost of computing and optimizes the cross-platform exchange of data.

The feature installs exclusively in the PCIe I/O drawer. Up to two zEDC Express features can be installed per PCIe I/O drawer domain. However, if the domain contains a Flash Express or 10GbE RoCE feature, then only one zEDC Express feature can be installed on that domain. For more information, see Chapter 7, “Shared Memory Communications” on page 125.

Between one and eight¹ features can be installed on the system. There is one PCIe adapter/compression coprocessor per feature, which implements compression as defined by RFC1951 (DEFLATE).

A zEDC Express feature can be shared by up to 15 logical partitions (LPARs).

Adapter support for zEDC is provided by Resource Group code that is running on the system’s integrated firmware processor (IFP). For resilience, on zEC12 and zBc12 there are always two independent Resource Groups on the system, and they share the firmware processor. Therefore, a minimum of two zEDC Express features should be installed, with one for each group.

Also, consider the total data throughput that is required. If one feature becomes unavailable, the others must be able to absorb the load. For best data throughput and availability, install at least two features per Resource Group.

Availability rules have been relaxed for z14, z14 ZR1, z13, and z13s servers with the introduction of four Resource Groups. With four features installed, if one resource Group becomes unavailable due to firmware maintenance, only one zEDC feature is taken offline, the remaining three are capable of handling the workload with less performance impact.

For more information on resource group allocation for PCIe I/O drawers and PCIe+ I/O drawers (FC #4001) see the following publications:

Support of zEDC Express functions is provided by IBM z/OS 2.1 and later for data compression and decompression.

More and more programs are enabled to use zEDC. At the time of writing, the following programs and subsets of z/OS are supported:

z/VM V6.3 with PTFs and later provide guest exploitation support of the zEDC Express feature (0420) on the Z platform.

 

The IBM Z Batch Network Analyzer (zBNA) is a PC-based productivity tool for estimating the elapsed time for batch jobs. This estimation is based on the differences in processor speeds of a base processor and a target processor, the number of engines on each system, and system capacities. Data sharing is not factored into the estimate. It is available as-is, without charge.

zBNA replaces the BWATOOL. It works with the Microsoft Windows operating system and provides graphs and text reports, including Gantt charts, and support for alternative processors.

zBNA can be used to analyze your SMF records to identify jobs and data sets that are candidates for zEDC compression, across a specified time (typically, in batch mode). zBNA generates lists of data sets by job:

You can use the zBNA tool to determine which zEDC features that you need to use.

IBM Business Partners can download zBNA and related CPS tools from this IBM PartnerWorld® web page, which requires registration (at no charge):

IBM employees can download zBNA and related CPS tools from the IBM Z Batch Network Analyzer (zBNA) Tool web page: