IBM Mainframe Forum

Hi ,

We found a dataset was cataloged in both DASD and Tape with same name and different data.When we tried to access the dataset with only disp=shr , it refers DASD and we try with DISP ,VOL SER and UNIT parameter , it refers to tape dataset.

But when we tried to create a dataset in TAPE which is already cataloged in DASD , it deleted the dataset from DASD and created in TAPE .

Can a dataset be cataloged in both DASD and Tape with same name ?

Thanks,
Gautham

But when we tried to create a dataset in TAPE which is already cataloged in DASD , it deleted the dataset from DASD and created in TAPE .

Really? You did "DISP=(NEW,CATLG,DELETE)," and the step DELETED the previously cataloged DASD dataset! I never heard of this happening. I would think your step would abend for already being cataloged and/or get a Not Catlg 2 error.

Can a dataset be cataloged in both DASD and Tape with same name ?

No.

Each catalog entry must be unique. Hence it is not possible to have the same data set name cataloged on tape AND disk simultaneously.

And the behavior you described will not happen unless your site has some very unusual software installed. Attempting to catalog a tape using the same name should give you a NOT CATLGD message in your output -- it should NOT affect the disk data set.

Hi,

We tried creating tape dataset which is already existing in DASD through (NEw,CATLG,DEL) but dasd dataset got deleted and dataset was created in tape .

Please find the below attachment/image , which we took from QW . It explains a dataset can be present in both DASD and TAPE.

Thanks,
Gautham

gauthamnagpur18, I think you are EXTREMELY confused at this point. A data set may exist on many disk volumes and on many tape volumes AT THE SAME TIME (potentially, as many disk volumes and tape volumes as exist at your site). However, only one data set can be in the catalog -- for all the other data sets you would require a UNIT and VOL=SER= in order to reference them. They can still be accessed, but if you typically put DSN=???,DISP=SHR (or OLD or MOD) then you are accessing the data set that is in the catalog.

Hello,

This is not a generation dataset is it?

Different generations might be cataloged on different media and when a new generation is created, the oldest might "roll off".

Hi Robert Sample,

Thanks for clarifying the query .

Hi Dick,

No it is not a GDG .

Thanks,
Gautham