Mainframe Acronyms

zIIPs, zAAPs and IFLs, MIPS, MSUs and ICFs – if you’re in the know it makes good sense, otherwise it can sound like a lot of mumbo jumbo. Here’s a very brief run down on some of the terms used in the mainframe space.

First things first – Why System “z”?

“z”
Stands for zero downtime, with the machines being designed with full redundancy to ensure continuous operations.

CP
Central Processor

ICF
The Internal Coupling Facility – The hardware and software that turns an IBM mainframe Base Sysplex system into a Parallel Sysplex. It is made up of special microcode built into the machine, and the CFCC operating system (Coupling Facility Control Code) in a spare processor. Coupling Facilities can also be implemented as a stand-alone machine or in an LPAR logical partition.

IFL
The Integrated Facility for Linux is a central processor dedicated to Linux workloads.

MIPS
Millions of Instructions Per Second – used as a measure of a computer’s central processing unit performance

MSU
Million Service Units is a measurement of the amount of processing work a computer can perform in one hour. Most mainframe software vendors charge by MSUs consumed (“workload-based charging”) or by total MSU system capacity.

zAAP
The IBM System z Application Assist Processors provides an attractively priced execution environment for new web-based applications and SOA-based technologies.

zIIP
The IBM System z Integrated Information Processor is available on all System z10 and System z9 servers. It is designed to help free-up general computing capacity and lower overall total cost of computing for select data and transaction processing workloads for business intelligence (BI), ERP and CRM, and select network encryption workloads on the mainframe.

See also:  SDS, Dictionary of the Mainframe World (an exhaustive reference of 6,000 words, phrases, and abbreviations)