IBM Mainframe Forum Index
 
Log In
 
IBM Mainframe Forum Index Mainframe: Search IBM Mainframe Forum: FAQ Register
 

SPACE allocation for a new dataset


IBM Mainframe Forums -> JCL & VSAM
Post new topic   Reply to topic
View previous topic :: View next topic  
Author Message
iknow

Active User


Joined: 22 Aug 2005
Posts: 411
Location: Colarado, US

PostPosted: Fri Nov 04, 2005 6:46 am
Reply with quote

hi folks
How much SPACE to specify in JCL for a "new" dataset? Explain with an example.
Back to top
View user's profile Send private message
Kevin

Active User


Joined: 25 Aug 2005
Posts: 234

PostPosted: Fri Nov 04, 2005 7:01 pm
Reply with quote

Normally, you don't specify space, as the System Managed Storage (SMS) system handles that task.

If. however, you wish to override that, then the answer will depend on your shop's standards. In our shop, space is calculated as follows:

Primary Tracks = (LRECL * MAX # of records) / 56664
Primary Space = (BLKSIZE / LRECL) * 2 * Primary Tracks
Primary Space = Primary Space / 1000

Secondary Tracks = (LRECL * (MAX # of records * .2)) / 56664
Secondary Space = (BLKSIZE / LRECL) * 2 * Secondary Tracks
Secondary Space = Secondary Space / 1000

so, space is allocated like this:
Code:

//         SPACE=(LRECL,(Primary Space,Secondary Space),RLSE),AVGREC=K
Back to top
View user's profile Send private message
mmwife

Super Moderator


Joined: 30 May 2003
Posts: 1592

PostPosted: Sun Nov 06, 2005 8:28 am
Reply with quote

Hi IK,


You can economize by using BLKSIZE and secondary allocations, but the bottom line is "it depends on how many and how big the recs your new file might be."
Back to top
View user's profile Send private message
View previous topic :: :: View next topic  
Post new topic   Reply to topic View Bookmarks
All times are GMT + 6 Hours
Forum Index -> JCL & VSAM

 


Similar Topics
Topic Forum Replies
No new posts Replace each space in cobol string wi... COBOL Programming 2
No new posts FINDREP - Only first record from give... DFSORT/ICETOOL 3
No new posts CLIST - Virtual storage allocation error CLIST & REXX 5
No new posts Map Vols and Problem Dataset All Other Mainframe Topics 2
No new posts Allocated cylinders of a dataset DB2 12
Search our Forums:

Back to Top