How %used is calculated for REXX Datasets

karthik-guruprasad · New User Joined: 17 Apr 2007 Posts: 6 Location: chennai

My dataset name is

Data Set Name . . . : CEC.GY338.REXX

General Data Current Allocation
Volume serial . . . : TS004E Allocated blocks . : 6
Device type . . . . : 3390 Allocated extents . : 1
Organization . . . : PO Maximum dir. blocks : 40
Record format . . . : FB
Record length . . . : 80
Block size . . . . : 27920 Current Utilization
1st extent blocks . : 6 Used blocks . . . . : 3
Secondary blocks . : 10 Used extents . . . : 1
Used dir. blocks . : 1
Creation date . . . : 2007/04/18 Number of members . : 2
Referenced date . . : 2007/04/24
Expiration date . . : ***None***

When you see the percentage used it is 66% .How this is calculated and more over when it comes to cylinder how will that be calculated.

Command - Enter "/" to select action Tracks %Used
-------------------------------------------------------------------------------
CEC.GY338.REXX 3 66

Can Anyone explain how this is calculated

dick scherrer · Posted: Thu Apr 26, 2007 6:20 am

Hello,

"REXX" datasets (if i understand your question) are no different than other partioned datasets.

The % used is calculated by taking the amount of space used and dividing by the total space. Using that answer (a percent), you can subtract from 100 and see the % of space used and the free space %.

Keep in mind that a pds may be "full" with only one member. This is because space is not dynamically reclaimed when an updated version of a member is saved. Compressing the library will "free" the unused space.

Cylindars may calculated by dividing the number of tracks by 15. Keep in mind that different device types have different capacities, so the "same" space allocation will allocate different amounts of physical space - check with your storage management people for which device types your location uses. I'd suggest you look at this prior topic:
http://ibmmainframes.com/viewtopic.php?t=17868

If i misunderstood your question, please ask for more.

expat · Posted: Thu Apr 26, 2007 1:04 pm

The other thing to remember is that in a PDS/PDSE the directory will also take up some space.

FOR PDS - The usual rate of consumption for a 3390 is that one track will accomodate 45 directory blocks, with each directory block containing 6 members with stats on or 8, I think, with stats off.

The only anomoly with this is allocation that the first track of directory will only accomodate 44 directory blocks.