IBM Systems Magazine, Mainframe - January/February 2015 - (Page 36)

TECH CORNER For a Quick, Quality Copy, Use FLASHCOPY IMAGE COPY Using the data availability function makes sense for some environments M ore customers are asking about FlashCopy* Image Copy (FCIC). Although first introduced in DB2* 10 for z/OS*, clients have been slow to convert any traditional image copies to FCIC. Much of the hesitation comes from misunderstandings of the process, restrictions and the all-important question: What does it really buy me? John Iczkovits is a member of IBM's DB2 Advanced Technical Skills team. A Simple Process The process, although seemingly daunting, is simple. The DB2 COPY utility is invoked with the FLASHCOPY YES or CONSISTENT keyword, along with the optional keyword FCCOPYDDN. Many customers believe that FCIC has the same restrictions and requirements as System Level Backup (SLB), but some key differences exist. FCIC requires DFSMSdss but, unlike SLB, it does not require DFSMShsm or SMS Copy Pools. Restrictions and options are outlined in the DB2 utility and installation manuals for the subsystem parameters (ZPARMs) and utility keywords required for FCIC. Fully read and understand all of the requirements and options before using FCIC. One of the major requirements for FCIC is FlashCopy V2, a disk cost product, which allows for data set level flash copies. IBM supplies all competitor disk vendors with a FlashCopy API, allowing FCIC to execute on any disk regardless of the manufacturer. 36 // JANUARY/FEBRUARY 2015 Unfortunately, storage administrators don't have an easy way of determining if FlashCopy V2 is installed outside of running a DFSMSdss COPY job. Many times the product is bundled with other products purchased and never executed. Successful invocation of FlashCopy will be denoted in the job output with the message ADR806I - DATA SET 'n' COPIED USING A FAST REPLICATION FUNCTION. From an IBM disk perspective, the source (table/index space) and target (FCIC) data sets must reside on the same disk box. Customers with hundreds or thousands of logical volumes in the same SMS Storage Group across different disk boxes will have a hit or miss result for the fast replication. If by luck the source and target volumes are on the same disk box (source and target may reside on the same logical volume), fast replication is used. On the other hand, if they reside on different disk boxes, DFSMSdss will be invoked as a track copy (slow), no FlashCopy establish will be performed and no fast replication will take place. Successful completion for copies inside or outside the box will look similar. Job step return code 0, where the source (table/index space) and target (FCIC data set) reside in the same disk box, contains job output message ADR806I. Return code 0, where the source and target don't reside in the same disk box, won't contain job output message ADR806I. Both will have the same entry in SYSCOPY; column ICBACKUP has the value FC. In this case FC doesn't denote whether FlashCopy successfully completed an establish, rather that's denoted by the keywords FLASHCOPY YES or CONSISTENT. With a very recent change, APAR PI20992 will now update column COPYLASTTIME in the Real Time Statistics when FCIC successfully completes. Traditional image copies create a sequential output data set based on the used size of the object being copied rather than the allocated size. With FCIC, the DB2 COPY utility invokes

Table of Contents for the Digital Edition of IBM Systems Magazine, Mainframe - January/February 2015

Table of Contents
Editor's Desk: A new mainframe
IBM Perspective: Embracing mobile with z13
Partner PoV: Align existing competencies with intuitive best practices
Focus on Storage: IBM System Storage DS8870 delivers workload efficiency as the amount of information increases
Currents: Small changes in recent z/OS releases can result in big improvements
Case Study: A Sky-High Education: Marist College uses the cloud to offer massive open online courses
Cover Story: Game Changer: New z13 is optimized for mainframe clients' mobile, analytics and cloud needs
HotTECH Products
Feature: A Clustered Support System: IBM delivers the flexibility and data availability of Elastic Storage to Linux on System z
Tech Corner: Using the data availability function makes sense for some environments
Solutions: Accelerator for.NET 5.0; TASKLIB+ and Launch Express; Express Entry Global Address Verification
Stop Run: A Lego version of the zEnterprise 114 is transformed into a working 'mainframe' model
Reference Point - Global Events, Education, Resources for Mainframe
2015 Mainframe Solutions Edition Product Index

IBM Systems Magazine, Mainframe - January/February 2015