Release Space after SNAP



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Release Space after SNAP

Postby Number1Ump » Sat Nov 03, 2012 1:15 am

Hi all,

In our shop, we use EMCSNAP. Mainly our folks use it for copying VSAM files, but I am working on snapping some sequential files. What I am finding is that after the snap completes, unused space is not released. For example:

//PS0150   EXEC PGM=EMCSNAP                                           
//******************************************************************* 
//ZEBBNR   DD  DUMMY                                                   
//SYSPRINT DD  SYSOUT=*                                               
//SYSTERM  DD  SYSOUT=*                                               
//DD01     DD  DSN=SCTD.TSTE.PSW.STMT.SCSTMTS.IM,                     
//             DISP=SHR                                               
//*D01O    DD  DSN=&OSCPD..PSB.STMT.SCSTMTS.IM.&TM&GDG1,               
//DD01O    DD  DSN=SCTD.TSTE.PSB.TEST.GDG(+1),                         
//             DISP=(,CATLG),                                         
//             SPACE=(CYL,(1000,250),RLSE),                           
//             DCB=(RECFM=FB,BLKSIZE=0,LRECL=800,DSORG=PS)             
//QCOUTPUT DD  SYSOUT=*                                               
//QCINPUT  DD  *                                                       
    GLOBAL MAXRC(4)             -                                     
           HCPYMODE(SHR)        -                                     
           REUSE(N)             -                                     
           REPL(Y)              -                                     
           MIG(PUR(Y)REC(Y))    -                                     
           COPYSMS(DATACLAS STORCLAS)                                 
    SNAP DS(INDD(DD01) -                                               
            OUTDD(DD01O))     


Some days, this file is at least 1000 cylinders, if not more. Somedays it is smaller. I have tried various SNAP commands and review the documentation in detail and have not found anything that would make this space release although the RLSE is coded on the SPACE parameter.

Any thoughts?
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Re: Release Space after SNAP

Postby NicC » Sat Nov 03, 2012 1:24 am

Code a smaller primary allocation as not all the allocation is (usually?) used. Let the secondary take care of larger than usual data volumes. Also, using a smaller prime gives SMS more flexibility in allocating space to your dataset.
The problem I have is that people can explain things quickly but I can only comprehend slowly.
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Re: Release Space after SNAP

Postby dick scherrer » Sat Nov 03, 2012 1:31 am

Hello,

Tha utility may be designed to always take the full first extent? Unused secondaries might be released.

Just a guess - we don't use BMC.
Hope this helps,
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Re: Release Space after SNAP

Postby Akatsukami » Sat Nov 03, 2012 1:45 am

Is the output data set of a SMS management class that inhibits release of allocated space?
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Re: Release Space after SNAP

Postby toulousian » Mon Apr 08, 2013 10:47 pm

EMC user,

I don't have an answer for your problem with reclamation, but I have a question that you can answer. I am working on a project that converts EMC SNAP to using HP Flashcopy and I can't find any recent EMC timefinder SNAP manuals.

Specifically, I am looking for an option in timefinder via JCL called COPYSMS(DATACLASS) as I understand it deals with the what SMS options like dataclass, smsclass and ect.

Do you have a new timefinder manual or could you copy the section on COPYSMS for me please ?? I have an August 2008 version of the Timefinder Mainframe SNAP product guide and I cannot find anything newer or anything that has COPYSMS in it.

BTW, did you get your reclamation problems fixed ?? Is this using SE volumes and thin provisioning ??

Shawn Shelton
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Re: Release Space after SNAP

Postby NicC » Mon Apr 08, 2013 10:59 pm

1) your post has been edited to remove your e-mail address. Of course, if you do not mind g spammed by everyone and their aunties it could be reinstated.
2) if you are registered to use the softwren you can obtain documentation for your level of the software free of charge from the Do not attempt to make someone break the law by asking for copyrighted material.
3) you should, probably, have started a new topic as this one is almost past its sell-by date.
The problem I have is that people can explain things quickly but I can only comprehend slowly.
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