How to determine approx size of dataset in Megabytes



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How to determine approx size of dataset in Megabytes

Postby D9988 » Fri Mar 06, 2009 11:05 pm

Hello. Is it possible to determine the approximate size of a dataset in megabytes based off the dataset information? I do not know if you can estimate this based off used cylinders alone, or if there is a formula that takes into account the record length along with the blocksize/used cylinders? Can anyone describe how to determine the file size based upon this data set information please?

General Data                           Current Allocation               
 Management class . . : I2WBRA1Y        Allocated cylinders : 100       
 Storage class  . . . : NORMAL          Allocated extents . : 2         
  Volume serial . . . : PT9C57                                         
  Device type . . . . : 3390                                           
 Data class . . . . . : **None**       Current Utilization             
  Organization  . . . : PS              Used cylinders  . . : 63       
  Record format . . . : FBA             Used extents  . . . : 2         
  Record length . . . : 133                                           
  Block size  . . . . : 931                                           
  1st extent cylinders: 50                                           
  Secondary cylinders : 50                                           
  Data set name type  :                 SMS Compressible  :   NO       
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Re: How to determine approx size of dataset in Megabytes

 

Re: How to determine approx size of dataset in Megabytes

Postby dick scherrer » Sat Mar 07, 2009 12:23 am

Hello,

One easy way for a small file like this is to copy the file to a DD DUMMY output which will give you the record count (without actually creating a new file). Then multiply the recount times the lrecl and you get file size in bytes. Dividing total bytes by 1024 will give how many k/m bytes.

The other way to calculate the size is to determine how many blocks will fit onto a track and work from there. Look at the info at this link:
http://publibz.boulder.ibm.com/cgi-bin/ ... 1001/B.1.2
"Without keys" is for normal sequential files.
Hope this helps,
d.sch.
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Re: How to determine approx size of dataset in Megabytes

Postby D9988 » Thu Mar 12, 2009 2:28 am

Thanks Dick, very helpful information :)
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