Restart JCL for a GSAM GDG

Hal2001 · New User Joined: 06 Jun 2006 Posts: 4

Can anyone tell me how the GDG is affected when you do a restart?
Should an output GSAM DB DD look like this?

//GSAM DD DSN=TEST.CUSTOMER.D00010(+1),
// UNIT=SYSDA,
// DISP=(NEW,CATLG,CATLG),
// SPACE=(CYL,(25,50),RLSE),
// DCB=(MODELDCB.NOATTRIB,RECFM=VBS,LRECL=23036,BLKSIZE=27992)

What would you have to do to the JCL if you need to do a restart? Does the GDG version become (0)? How does that impact the file Disposition since the file will be read for the restart but once the restart is positioned the output file will continue to be written too? Using the example above would the DD look like this on a restart?

//GSAM DD DSN=TEST.CUSTOMER.D00010(0),
// UNIT=SYSDA,
// DISP=(MOD,CATLG,CATLG),
// SPACE=(CYL,(25,50),RLSE),
// DCB=(MODELDCB.NOATTRIB,RECFM=VBS,LRECL=23036,BLKSIZE=27992)

gautam79 · New User Joined: 30 Aug 2006 Posts: 11 Location: India

Dont forget to change the GDG version number to 0.

shreevamsi · Posted: Wed Aug 30, 2006 1:50 pm

hi Hal2001,

Where is the RESTART happened. Is it in a SCHDULER in PRODUCTION or a batch we submit in out testing region.

If you use RESTART in SCHDULER, The SCHDULEr takes care of the GDG versions. But in Test, You already be knowing.

~Vamsi

PascalQ · New User Joined: 12 May 2006 Posts: 20

Hal2001,

Usually the scheduler at your site considers adjustments for GDGs in case of restart.

Handling GDG restarts manually is not very handy. Let us know which scheduler you use.

abinash_mohapatra · New User Joined: 28 Mar 2005 Posts: 7 Location: Bangalore

Hi,

During restart of an IMS program, one needs to take special attention if the IMS program is using the GSAM files. If the program is using GSAM files, following points should be taken into consideration for the extended restart features.

1. Always create the sequential file (which is to be used as GSAM files in the IMS program) in the previous step by using IEFBR14 utility rather than creating in the actual program execution step.
2. In the actual program execution step, use DISP=(OLD,KEEP,KEEP) to use the GSAM files for both normal execution as well as for restart. If you use other DISP paramaters, then restarting might not give you the actual result.
3. Before restar, do not open or edit the same file. This is just to ensure that, database pointer set in GSAM files will not be lost.
4. If you are using the GDG files, just change the GDG version to "0" before restart.

Hope, this will help you.

Regards
Abinash