1. Storing and Managing Data in Today’s z/OS Environment
Michael E. Friske

2. Storage Challenges Compounded growth Cost reduction pressure
Changing regulatory and business requirements
Higher availability requirements
Data life cycle management

3. Hardware Solutions That Can Help Address These Challenges
Storage Tiering
IBM DS8870 with EasyTier
EMC VMAX with FAST
HDS VSP with HDS Dynamic Tiering
Virtual Tape
IBM DS7700
Oracle VSM
EMC DLm
CA-Vtape (software/hardware)

4. Traditional Storage Hierarchy
High Performance
Cache or SSD
Enterprise Disk
ML1 Disk
ML2 Tape
Low Cost

5. Data Life Cycle Active data Less active data Inactive data
Stored on primary disk
Less active data
Migrate to ML1 disk
Uses MIP’s
Must be recalled to use
Inactive data
Migrate to ML2 tape
Must recall to use
Primary Disk
ML1
Disk
ML2
Tape

6. SMS MGMTCLAS Number of days on primary disk
Number of days on ML1 volumes
When to expire
Management criteria
Number of days since the create date
Number of days since the last reference date

7. Disk Options Flash Drives (100GB, 200GB, 400GB, 1.6TB, and 3.2TB)
Solid State Drives (400GB)
SAS Drives
10,000 RPM (300GB, 600GB, 900GB, and 1.2TB
15,000 RPM (146GB and 300GB)
Nearline SAS Drives
7,200 RPM (1TB, 2TB, 3TB, and 4TB)

8. Determining What Data Went on Which Drives
Disk subsystems with a mix of different types of disk drives
Analyze RMF and/or SMF reports
Map SMS storage groups to specific disk drives
Monitor for changes in access patterns
A homogenous disk subsystem that works for all types of data

9. Hardware Based Tier Management
IBM DS8870
EMC VMAX
HDS VSP
Easy Tier
Fully Automated Storage Tiering (FAST)
HDS Dynamic Tiering

10. First Generation Tiering
The Disk subsystem monitored the I/O activity for each extent
Extents were dynamically relocated to different tiers based on internal algorithms

11. Shortcomings of First Generation Tiering
Data is moved at the extent level, not on a data set boundary
Data sets move around due to reorgs, defrags, copying, etc.
Patterns of access change based on the time of day or the day of the week
Data is placed on a storage tier based on access, not SLA’s

12. Addressing the Shortcomings
Hints from the host
z/OS 2.1 Class Transitions
Hitachi Tiered Storage Manager

13. MGMTCLAS - Expiration

14. MGMTCLAS - Migration

15. MGMTCLAS – Class Transition

16. MGMTCLAS – Transition Technique

17. Easy Tier with Class Transition
Enterprise $
Class transition after 120 days
Nearline
½ $
Recall
Migrate after 366 days

18. Transition Copy Technique
FRP - FR PREFERRED
FRR - FR REQUIRED
STD - STANDARD
PMP - FC PRESMIRPREF
PMR - FC PRESMIRREQ

19. Serialization Error Exit
DB2 - Invoke DB2 to close and unallocate the object. If this is successful, the object is serialized and moved and DB2 is invoked to reopen the object.
CICS - Invoke CICS to take the object offline. If this is successful, the object is serialized and moved and CICS is invoked to reopen the object.
ZFS - Invoke zFS to unmount the data set. If this is successful, the data set is serialized and moved and zFS is invoked to remount the data set.
EXIT - Enables users / ISVs to provide an exit that will be invoked before and after transitioning an allocated data set. The data set is only transitioned if serialization is obtained after the first invocation of the exit.
NONE

20. Transition Invokes the ACS Routines
Once DFSMShsm determines that a data set has met the Class Transition criteria specified by the Management Class, it invokes the ACS routines to determine what the transition should be
ACS Routines are invoked with new ACS environment (&ACSENVIR) of SPMGCLTR, for 'space management class transition'
The following routines are invoked (in this order)
Storage Class
Management Class
Storage Group
Any or all can be transitioned
If the classes and storage group returned match the existing classes and storage group, then no transition occurs

21. STORCLAS Routine IF &ACSENVIR = 'SPMGCLTR' THEN SELECT (&STORCLAS)
WHEN (‘FLASH') SET &STORCLAS = 'EASYTIER'
OTHERWISE SET &STORCLAS = &STORCLAS
END
ELSE ...
IBM

22. MGMTCLAS Routine IF &ACSENVIR = 'SPMGCLTR' THEN SELECT (&MGMTCLAS)
WHEN ('NOML2') SET &MGMTCLAS = 'ML2OK'
WHEN ('DB2NEW') SET &MGMTCLAS = 'DB2AGED'
OTHERWISE SET &MGMTCLAS = &MGMTCLAS
END
ELSE
...
IBM

23. STORGRP Routine IF &ACSENVIR = 'SPMGCLTR' THEN SELECT (&STORCLAS)
WHEN (‘FLASH') SET &STORGRP = 'TIER0'
WHEN ('EASYTIER') SET &STORGRP = 'TIER1'
OTHERWISE SET &STORGRP = &STORGRP
END
ELSE ...
IBM

24. Example – New Data Set Flash Enterprise Nearline Initial access
Random reads & writes with periods of high access
STORGRP = TIER0
Flash
Enterprise
MGMTCLAS
No migration
Transition after 60 days
Flash
Enterprise
TIER0
Nearline
TIER1

25. Example – Access Drops Off
Access after 3 months
Accessed less
No write activity
STORGRP = TIER1
Enterprise
Nearline
MGMTCLAS
Migrate after 30 days of inactivity
Expire after 7 years
Transition after 60 days
Flash
Enterprise
TIER0
Nearline
TIER1

26. Example - Inactive Flash Enterprise Virtual Tape Nearline TIER0 TIER1
Recall
Nearline
Migrate
TIER1

27. Cost Savings Reduce CPU costs by eliminating ML1
No need to compress or decompress data
Eliminate recalls from ML1
Reduce CPU costs with Class Transition
May be able to use FlashCopy
May be able to wait longer before migrating to ML2
Reduce the purchase price for new disk subsystems

28. Virtual Tape Subsystems
IBM TS7720
EMC DLm
Oracle VSM

29. Cost Reduction with Virtual Tape
Reduces floor space requirements
Reduces the need for tape handlers
Replicate tape data to remote site for disaster recovery
Batch cycle runs faster
Tapeless tape subsystems
Eliminate the need to tape handlers
No need to buy physical tape media

30. zEnterprise Data Compression
zEDC Express is an IO adapter that does high performance industry standard compression
Used by z/OS Operating System components, IBM Middleware, and ISV product
Required z/OS 2.1 and EC12 or BC12

31. SMS Compression with zEDC
Can be used in place of generic or tailored compression for QSAM and BSAM data sets
CPU savings for existing users of SMS compression
Disk savings for users who are not currently using SMS compression

32. Other Features That Can Reduce HSM CPU Consuption
Use RLS to access the HSM CDS’s
Replace Interval Migration with On-Demand Migration
Take advantage of Multiple Address Space HSM (MASH) support
Implement the Common Recall Queue
Implement Fast Subsequent Migration
Avoid reorganizing the HSM CDS’s too frequently
HOLD LOG if log data is not required

33. RLS for HSM CDS’s
Reduces CPU overhead for HSM due to less calls to GRS, less buffer invalidation, and less I/O to disk
Reduces elapse times for long running tasks like Primary Space Management, Secondary Space Management, EXPIREBV, Recycle, and Audit

34. HSM On-Demand Migration
Does not check every volume each hour to see if the volume is over the high threshold
Eliminates the spike in CPU usage for HSM at the top of each hour
Will only process a volume once after it goes over the high threshold

35. HSM MASH
Can be used to run HSM backup and space management functions at a lower priority (different WLM Velocity Goals)
Can be used to spread tasks out to more address spaces and to reduce SYSZTIOT contention

36. HSM Common Recall Queue
Allows multiple hosts to process recalls
Can be used to limit tape processing on certain CPU’s
Helps with workload balancing
Multiple recalls for different data sets on the same tape from different CPU’s can be processed on a single CPU
Allows higher priority requests across the sysplex to get process first over lower priority requests
Keeps recall requests if HSM is shut down or goes down unexpectantly

37. Fast Subsequent Migration
Saves CPU costs associated with re-migrating data sets that were recalled but not updated
Reduces the need to run RECYCLE

38. HSM CDS Reduction Turn on CA Reclaim for the HSM CDS’s
Do not reorganize the HSM CDS’s just because they have CI and CA splits
Only reorganize the HSM CDS’s to reclaim space

39. Other Cost Avoidance Measures
Clean up the errors HSM finds each night
Analyze MGMTCLAS definitions periodically, and adjust them if necessary
Check for data sets in the wrong MGMTCLAS

40. Data That Can Be Used for Analysis
HSM Logs
HSM FSR records
DCOLLECT data

41. Questions ?