Mainframe Resource Optimization

DASD Reduction Ideas


Migrate to Disk Candidates Examples:
1) Big DSNs that have not been referenced for 3 weeks and are not in a monthly process.
2) GDGs less than -7 generation that are older than 7 days.
3) Test DSNs that haven't been referenced since their creation date older than 3 days bigger than 1 MB.

Space Release  Candidates Examples:
1) Big sequential DSNs that have not been referenced for 1 week and are not in a weekly process.
2) Sequential GDGs less than -2 generations that are older than 1 days with any free space at all..
3) Empty DSNs that didn't been referenced since their creation date older than 3 days bigger than 1 MB.

Delete Candidates Examples:
1) TEST Big EMPTY DSNs that have an error in DSORG or BLKSIZE that have been created more than 1 week ago and are not in a weekly process. They have never been referenced since they were created.
Further checks could include batch vs online, sequential vs partitioned and not a temporary file.
These problem files can not be migrated using HSM, can not have the space 'freed' up using TSO
and can not even be browsed. You may not want to actually delete these datasets - Maybe just feed them into generated JCL to actually free the wasted space and fix DSORG while your at it.

Exception Reporting  Examples:
(Just get the Top 50 or so of each to reduce too much paper and overwelming cleanup drudgery.)

1) Biggest  DSNs over 1000 cylinders (make sure no 4.2 GB limit encroachments).
2) Fullest   DSNS (80-99%)   (maximum extents expected?).
3) Freest   DSNS  over 1000 tracks or 80%  (space release candidates?)
4) Oldest  DSNs  never referenced for 2 years (migration candidate?)
5) High Extents (Sequential: over 10 ,  VSAM: Over 50 )
6) High CI/CA Splits   (Prod: Over 10,  Test: Over 100)
7) Inadequate Secondarys  (Less than 3% of allocated amount )
8) DSNS with Problems   (Catalog, Blksize, DSORG etc).

RIGHT Size  Examples:
1) Test file allocations will be only 5% more than what is expected with only 2% internal free space.
2) Creating smaller environments for developers can save DASD as well as CPU.
3) Developers should have a habit of testing with 'file record counters' for faster turnaround.
 
 




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Last Updated on 11/29/2000
By kwills
Email: kwills14@comcast.net