Portal | Manuals | References | Downloads | Info | Programs | JCLs | Master the Mainframes
IBM Mainframe Computers Forums Index
 
Register
 
IBM Mainframe Computers Forums Index Mainframe: Search IBM Mainframe Forum: FAQ Memberlist Usergroups Profile Log in to check your private messages Log in
 

 

How can I determine the space for data set on tape?

 
Post new topic   Reply to topic    IBMMAINFRAMES.com Support Forums -> JCL & VSAM
View previous topic :: :: View next topic  
Author Message
saturn

New User


Joined: 30 Jun 2006
Posts: 9
Location: Germany, Eschborn

PostPosted: Wed Aug 20, 2008 11:38 am    Post subject: How can I determine the space for data set on tape?
Reply with quote

How can I determine the space allocated by a given data set on tape? We have to decide if it is useful to store data on tape or on DASD. We already have a lot of data on tape an now we must determine the allocated and used space for these data sets.
For the data on hard disk I can retrieve these information from LISTDSI and LMDLIST. I also tried to use the catalog search module IGGCSI00 but a got only 'FFFFFF' as result for the primary and secondary allocated space.
How can I collect the space consumption on tape without reading the data it self?

Best Regards
Joern Fischer
Back to top
View user's profile Send private message

expat

Global Moderator


Joined: 14 Mar 2007
Posts: 8593
Location: Back in jolly old England

PostPosted: Wed Aug 20, 2008 12:07 pm    Post subject:
Reply with quote

If you know the lrecl and blocksize and the number of blocks used (usually from your TMS) you can guess-timate it.

Blocks used * INTEGER(blocksize / lrecl) will tell you roughly how many records there are.

Then it's INTEGER(27998 / lrecl) * 2 which gives number of records per 3390 track

So - record estimate / recs per track = tracks required

tracks required / 15 = cylinders required.
Back to top
View user's profile Send private message
saturn

New User


Joined: 30 Jun 2006
Posts: 9
Location: Germany, Eschborn

PostPosted: Fri Aug 22, 2008 12:31 pm    Post subject: Reply to: How can I determine the space for data set on tape
Reply with quote

Thanks for the detailed reply! This method is a good idea, but I am not sure if this can help me.
The most of our data sets are variable blocked. From my understanding I can use this rule also for VB’s?
I am not sure but I think our data on tape are compressed. If so, I can’t calculate the space from the block size and record length. Correct?
I have to clarify which TMS we are using and if there is any possibility to call the TMS service via REXX. I have to investigate approximately 300 data sets, this can't be done in a manually process.
Back to top
View user's profile Send private message
expat

Global Moderator


Joined: 14 Mar 2007
Posts: 8593
Location: Back in jolly old England

PostPosted: Fri Aug 22, 2008 12:43 pm    Post subject:
Reply with quote

Whether the tape data is compressed or not, the result should still be reasonably accurate. Although the data in compressed, the number of blocks used will remain the same.

For VB files, the maximum LRECL will probably give a result which is slightly higher than required, but contingency is never a bad thing icon_wink.gif
Back to top
View user's profile Send private message
Anuj Dhawan

Senior Member


Joined: 22 Apr 2006
Posts: 6258
Location: Mumbai, India

PostPosted: Fri Aug 22, 2008 1:53 pm    Post subject:
Reply with quote

Hi,
Quote:
I have to clarify which TMS we are using and if there is any possibility to call the TMS service via REXX.
Other alternate can be invoking below code
Code:
//STEP010  EXEC PGM=SYNCTOOL/ ICETOOL
//TOOLMSG  DD  SYSOUT=*           
//DFSMSG   DD  SYSOUT=*           
//DD01     DD  DSN=TAPE_FILE_NAME,
//             DISP=SHR           
//TOOLIN   DD  *                   
   COUNT FROM(DD01)               
/*                                 
//*                               


Check the DFSMSG after execution of the code, it'll give you the LRECL & BLOCKSIZE of tape file. Perhaps that info can be of your use.
Back to top
View user's profile Send private message
expat

Global Moderator


Joined: 14 Mar 2007
Posts: 8593
Location: Back in jolly old England

PostPosted: Fri Aug 22, 2008 2:06 pm    Post subject:
Reply with quote

Anuj

Probably a little more accurate, but that does involve reading each tape file, some of which can be rather large.

IMHO the guess-timate method would be much quicker and would not use rather a lot of resource.

From a single listing from the TMS the guess-timate can be calculated for every tape in one pass and use a lot less resource. Especially if you work in a bill per usage site.
Back to top
View user's profile Send private message
saturn

New User


Joined: 30 Jun 2006
Posts: 9
Location: Germany, Eschborn

PostPosted: Sat Aug 23, 2008 2:41 pm    Post subject:
Reply with quote

Quote:
Probably a little more accurate, but that does involve reading each tape file, some of which can be rather large.

Yes I can't read each data set, especially if I have not the slightest idea how be big they are. Nevertheless the sort is not a bad idea. I keep it in view for possibly other requirements.

Could give me a dcollect report the statistics about the data sets on the tape? I asked our work bench about the TMS, but I have to contact the space management.

Thanks and regards Joern
Back to top
View user's profile Send private message
expat

Global Moderator


Joined: 14 Mar 2007
Posts: 8593
Location: Back in jolly old England

PostPosted: Sat Aug 23, 2008 3:04 pm    Post subject:
Reply with quote

The sort solution will read the tapes.

The TMS reports could probably be produced by yourself via a batch job. The best thing is to talk to your storage team and see what they say. When I have had people come to me and say I need this information, I usually give them the job to run for themselves.
Back to top
View user's profile Send private message
View previous topic :: :: View next topic  
Post new topic   Reply to topic    IBMMAINFRAMES.com Support Forums -> JCL & VSAM All times are GMT + 6 Hours
Page 1 of 1

 

Search our Forum:

Similar Topics
Topic Author Forum Replies Posted
No new posts Replace values in the input data Vikas Maharnawar DFSORT/ICETOOL 10 Thu May 11, 2017 2:18 pm
No new posts Group Data based on a key Arun Raj DFSORT/ICETOOL 7 Thu Apr 27, 2017 11:29 pm
No new posts unload data from table with lob columns farhad_evan DB2 0 Sat Apr 22, 2017 1:32 pm
No new posts VSAM Space Allocation mrgnndhmk JCL & VSAM 7 Sat Apr 22, 2017 12:42 am
No new posts Length of Tape file Mohan Kothakota JCL & VSAM 9 Thu Apr 20, 2017 10:24 pm


Facebook
Back to Top
 
Mainframe Wiki | Forum Rules | Bookmarks | Subscriptions | FAQ | Tutorials | Contact Us