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Eliza · Beginner Joined: 28 May 2007 Posts: 8 Topics: 1

Hi ,
I came across an error while taking backup of a file using ADRDSSU.

Wht my job was doing?
I had 10 tape files (GDG versions - say, MY.GDG.BKUP.G000V001 to 10) which were the back up taken for files MY.GDG.G000V001 TO 10.
I was trying to take the backup of MY.GDG.G000V007 on MY.GDG.BKUP.G000V007 again ( ie, i was trying to rewrite the tape file with the updated data in gen 7.) All the tape files were created in the same volume.

I got the error -
IECTMS3 0D16, 344021,IS NOT SCRATCH(56).
Explanation: This message indicates that the tape has been rejected for processing.The condition code (56) following the IECTMS3 message indicates the reasonfor the rejection and it says - An attempt has been made to create a secondary data set and a data set exists that
has a higher file sequence number.

As i mentioned before , all my tape files were in a single volume and had file sequence number from 1 to 10.(I had created it that way!!!!)

Resolution:
I recreated the tape files to diffrent volumes. And re submitted the job.
The job ran succesfully.

I want to know why this was happening - My understanding from this was if we have the generations of the same GDG in the same volume , ie n and n+1 with sequence number say 1 and 2 resp., then we will not be able to rewrite the tape file n.

Can some one give me a clear picture on this problem?

Cheers,
Eliza.......
.

warp5 · Posted: Wed May 30, 2007 2:40 am Post subject:

You can not rewrite tapes, it is that simple. How do you think that this could work? I think you need to learn some basics of how things work for a start.

Eliza · Beginner Joined: 28 May 2007 Posts: 8 Topics: 1

When i wrote 'rewrite' what i meant was, i took a back up a GDG gen say MY.GDG.G000V00x to MY.GDG.BKUP.G000V00x (x - 1to 10) and say , i updated the data in the seventh gen and i was trying to overrwrite the tape file (BKUP.G000V007) with the updated value.
And this is possible.

Cheers,
Eliza

Nic Clouston · Posted: Wed May 30, 2007 4:09 am Post subject:

Your tape has a retention period on it which means it cannot be overwritten until that date is reached or number of days has lapsed. Even if you did not specify a retention perios (LABEL=RETPD=xxx) your tape management system (TMS) will probably impart some sort of minimum.

If you need to reuse it before it has expired you have to tell your TMS that the tape can be reused.

(It may be that it will also have to rewrite the label at the front of the tape to say it is a scratch.)
_________________
Utility and Program control cards are NOT, repeat NOT, JCL.

Eliza · Beginner Joined: 28 May 2007 Posts: 8 Topics: 1

But I was able to overwrite the tape file, when I created the BKUP generations on different volumes. Only when there were more than one generation on the same volume, I was not able to overwrite the tape files.

kolusu · Posted: Wed May 30, 2007 7:00 am Post subject:

Eliza,

What is the JCL disposition used when you tried to rewrite the file?

Kolusu
_________________
Kolusu
www.linkedin.com/in/kolusu

Nic Clouston · Posted: Wed May 30, 2007 7:22 am Post subject:

You have multiple files on a tape and you are trying to overwrite one in the middle? Cannot be done - what if the new data is more than the old data - you will start to overwrite the next dataset - it is strictly sequential processing not write as much as you can and if you need more go to the end of all data and start writing. When you write to a new volume there is no data on it - what data is there can be overwritten. But you cannot write to an existing volume unless a) ALL data is to be regarded as expired or b) you write a new dataset after the existing last dataset.
_________________
Utility and Program control cards are NOT, repeat NOT, JCL.

Eliza · Beginner Joined: 28 May 2007 Posts: 8 Topics: 1

Hi,

For the BKUP file , I gave the disposition as DISP=OLD.

Thank u.

Eliza · Beginner Joined: 28 May 2007 Posts: 8 Topics: 1

Thanks Nic. Now I understand why the job was failing.
Just one more question. What does file sequence number indicate (one that we give in LABEL parameter).
My understanding is if we give the following label parameter LABEL=(1,SL,EXPDT=99000) then the job would actaully try to allocate the space in an empty volume

..... correct me if I am wrong!!!! Very Happy

Nic Clouston · Posted: Wed May 30, 2007 8:17 am Post subject:

Tapes consist of labels and data - labels identify a) the tape (volume serial number (tape number!)) b) the data - datset name dcb lrecl etc and HOW LONG BEFORE it can be used again. Label 1 refers to the first label and you are saying in this case that the data remains valid until 31st December 2098 and that the tape has Standard Labels.

There is a whole manual on tape labels so this is a brief and inaccurate, but good enough for the purpose, summary
_________________
Utility and Program control cards are NOT, repeat NOT, JCL.

Eliza · Beginner Joined: 28 May 2007 Posts: 8 Topics: 1

Thank you Nic.

Eliza · Beginner Joined: 28 May 2007 Posts: 8 Topics: 1

Can you please let me know any refrence manuals for understanding the tape fundas?

Phantom · Posted: Thu May 31, 2007 11:16 am Post subject:

Eliza,

Check this link.,

http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/DGT2M310/CCONTENTS?DT=20020118094117

Hope this helps,

Thanks,
Phantom

Eliza · Beginner Joined: 28 May 2007 Posts: 8 Topics: 1

Thank you