How to calculate the Space parameter for VSAm

venkatraman · New User Joined: 02 Jul 2006 Posts: 12

Hi,

can anyone explain how to calculate the Space parameter for both VSAm and Non Vsam dataset.

Thanks
venkat

expat · Posted: Sat Aug 25, 2007 11:56 am

What are the record attributes and lengths

venkatraman · New User Joined: 02 Jul 2006 Posts: 12

The RECFm is VB and the record length is 2004 for non vsam dataset

expat · Posted: Sat Aug 25, 2007 4:14 pm

VB records are not a "fixed" calculation as by the nature of its attributes the records do vary in length.

Taking 2004 as the maximum record length, and using a BLKSIZE of 27998 which is the optimum for 3390 DASD, you will get

27998 / 2004 = 13.971 records per DASD block = 13 complete records.
Obviously if some of the records are shorter than 2004 then there will be a few more records in the block(s)

2 blocks per track = 26 records per track.

15 tracks per cylinder = 390 records per cylinder.

So if you have 10,000 records

You will require 10000 / 390 = 25.64 ..... 26 cylinders

So for 10,000 records I would code SPACE=(CYL,(30,5),RLSE)

venkatraman · New User Joined: 02 Jul 2006 Posts: 12

Thank you[/img]