EOV abend

Selva-kumar · New User Joined: 01 Mar 2007 Posts: 52 Location: chennai

Hi,

I'm trying to do a repro on a KSDS file to a flat file (VB). The job abend with EOV abend and only few records ae copied. When i restarted again, the job ran succussfully.

Here are the attributes of the files:

Input KSDS file:

expat · Posted: Thu Dec 30, 2010 5:01 pm

It would appear that volume fragmentation could be the cause of your abend here

PeterHolland · Posted: Thu Dec 30, 2010 5:04 pm

My guess is that your blocksize is not a multiple of 904 plus 4.

Selva-kumar · New User Joined: 01 Mar 2007 Posts: 52 Location: chennai

Expat,

What could be done to prevent this. can the allocation of the file be increased?

expat · Posted: Thu Dec 30, 2010 5:23 pm

Peter, I doesn't have to be for a VB file.
I always use 27998 for VB files

Selva-kumar · New User Joined: 01 Mar 2007 Posts: 52 Location: chennai

Hi,

I also like to add up the following point. In first case (when job abends), the extents in 5 volumes are as follows:

Vol1 - 4 extents
Vol2 - 1 extent
Vol3 - 6 extent
Vol4 - 16 extent
Vol5 - 16 extent

In the second case(when job is successful), the extents in the 3 volumes ae as follows:

Vol A - 16 extent
Vol B - 16 extent
Vol C - 8 extent

These three volumes are different from the first 5 volumes that were used.

expat · Posted: Thu Dec 30, 2010 5:56 pm

PeterHolland · Posted: Thu Dec 30, 2010 6:06 pm

Expat,

thats right. After scanning some of my jcl libraries i found the same value for VB. Probably a mental remainder from the time i was an ICT virgin.

Selva-kumar · New User Joined: 01 Mar 2007 Posts: 52 Location: chennai

Thanks expat. I like to know how this can be prevented in future runs.

PeterHolland · Posted: Thu Dec 30, 2010 6:11 pm

Selva,

you could use dedicated volumes for your output. Or ask the storage people to do something about fragmentation.

Selva-kumar · New User Joined: 01 Mar 2007 Posts: 52 Location: chennai

I think i need to ask the storage group folks to do something to take care of the fragmentation. Thanks Peter

It would be helpful if you could point me any materials to understand the storage and volume allocation.

expat · Posted: Fri Dec 31, 2010 1:51 pm

If your storage people were anywhere near decent this fragmentation should not occur

Pete Wilson · Posted: Fri Dec 31, 2010 7:04 pm

You could increase the volume count by specifying VOLUMES(* * * * * * * * * *) in your define (same as VOL=(,,,10) in JCL) so the dataset can extend over further volumes as required. Sometimes doing that and reducing your allocation size a bit can help when you have fragmented volumes.

It might also help to assign a Dataclas that gives Extended Format as that increases the 16 extents per volume limit to 123 and removes the 65k tracks per volume size limit as well.

Remember that the old rules about the primary or first secondary extend having to be achieved in 5 chunks doesn't apply under later versions of SMS, they could be taken in many extents because of Space Constraint Relief. Add to that the automatic extent consolidation where two extents may be 'joined' on a subsequent extend if there's contiguous space next to the previous one and it starts to get a bit difficult to make sense of extents sometimes now.