Like all server systems, IBM's system-z mainframes need effective management to ensure operational costs stay as low as possible.
The problem, according to Gartner and Ovum, is that most large mainframe users see their processing power consumption increase by 15-20% annually in terms of million instructions per second (MIPS).
The additional hardware and software cost of purchasing every additional MIPS is around £2,500. So if a company running a 10,000 MIPS system increases capacity by just 10% per annum, the incremental cost will be in the region of £2.5 million, according to Lynda Kershaw, marketing manager at Macro 4, an IBM mainframe performance specialist.
However, she said it is possible to postpone upgrading the system by managing it well. "Mainframe users can cut or delay having to shell out millions of pounds on annual CPU capacity upgrades by using application tuning and performance management techniques to ensure their systems are using processing power efficiently."
Offloading to speciality engines
IBM itself suggests that system-z users can lower their mainframe costs by making use of mainframe speciality engines to share the processing load.
IFL allows Linux (and z/VM) workloads to be run on the mainframe; zAAP supports Java-based Web applications and XML services; and zIIP can offload different workloads such as certain DB2 data services, and process data mirroring and network encryption.
Doug Neilson, IBM Systems Consultant for IBM System z, said IBM does not impose software charges on zAAP or zIIP capacity. He added that customers are reporting "significant reductions" in mainframe Linux costs by using IFLs. Users with workloads suitable for offloading to zAAP and zIIP are seeing reduced total cost of ownership for their mainframes.
However, Mike Vinten, chief executive of System z consultancy Thesaurus, warned users of the dangers of offloading workloads to "lower-cost speciality processors".
"These problems can vary from technical and cost issues and even legal licensing complications. As appealing as the apparent hardware savings may be, additional incurred charges will actually result in no savings at all; in fact it will often prove to be more expensive," said Vinten.
Thesaurus recommends that organisations invest in the latest z-series platforms, such as the System Z10 Enterprise Class, which offer energy savings and scalability. "For example, we've just replaced Co-operative Financial Services' z9 systems with z10 to save the company £2m over three years in energy, maintenance and database costs."
According to Phil Jones, chief technology officer at Shoden Data Systems UK, lowering z-series mainframe costs often comes down to reviewing the organisation's mainframe applications.
He suggested calling for an audit of the top 50 applications in terms of MIPS used. "Ask the application owner why this is needed, and which department gets the benefit of this application. If charge-back were implemented, would this department pay for this application?"
Secondly, Jones said it is worth reviewing all the installed mainframe software licences. He said that one of Shoden's surveys showed that a UK bank had 53 mainframe software products from 39 different vendors. "Look at the Ts and Cs, call for a cull, and agree more aggressive financial terms with the vendors that are preferably not MIPs-based pricing," he recommended.
Companies can also reduce mainframe costs by looking for inefficient applications and code that use excessive CPU time. "By monitoring the applications as they run in real time or as a batch process, and identifying where the problems are, companies can often defer CPU upgrades for months, if not years," said Atul Bhovan, technology manager at Compuware.
"However, finding these problems can be made more difficult by the shrinking mainframe labour market. With the proliferation of other development languages, finding a competent COBOL developer or tester can be very difficult indeed. For this reason, many companies will consider outsourcing their mainframe management," he said.
Achieving mainframe cost efficiencies often comes down to good housekeeping, said Kikis Orphanos, manager of UK technical mainframe sales at CA.
It starts with using monitoring and systems management software, he said. Next, users should remove unnecessary functionality from systems software to reduce monitoring processes.
Deferring certain batch workloads, such as backups and stock consolidation, to quiet periods in the day will reduce the peak loads on the mainframe.
Finally, he urged users to regularly fine tune their applications and ensure that SQL-related activity is in hand. "SQL will increase overheads by as much as 100%, but good tuning can reduce overall processing requirements by as much as 50%," said Orphanos.