> I wanted to move some data off a tape labeled 000027.  I issued MOVE DATA
> 000027.  I then issued a Q PRO and the system responded that it was waiting
> for tapes 000027 and 000018.  Both tapes were mounted.  After a few minutes,
> I saw that tape 000027 unmount so I re-issued Q PRO and here's the output.
>
> adsm> q pro
>
>  Process Process Description  Status
>
>   Number
> -------- --------------------
> -------------------------------------------------
>        2 Move Data            Volume 000027 (storage pool TAPEPOOL), Target
>
>                                Pool TAPEPOOL, Moved Files: 0, Moved Bytes:
> 0,
>                                Unreadable Files: 0, Unreadable Bytes: 0.
>
>                                Current Physical File (bytes): 328,454
>
>                                Waiting for mount of input volume 000004 (8
>
>                                seconds).
>
>                                Current output volume: 000018.
>
> As you can see, ADSM was now waiting for tape 000004!  Now tape 000004 was
> mounted and, again, after a few minutes it was unmounted.  I looked in the
> actlog and the process for the MOVE DATA 000027 had completed successfully
> and the tape was now marked scratch.
>
> Can someone explain this?  Thanks in advance.

I am reasonably sure there was a two segment file starting on 000027 and
ending on 000004. That is, ADSM started writing the file on 000027, reached
the end of that tape, and wrote the remainder of the file on 000004. When ADSM
does a MOVE DATA from a volume containing part of a segmented file it reads
the entire file and writes it to the output volume or volumes, even if this
entails an extra input mount. I have also seen cases where the specified input
volume for a MOVE DATA started with the end of a segmented file, and a
different input volume was mounted before the specified volume in order to
read the beginning of the segmented file.