If you look up IGD07001I it says, among other things, to look at IDC3009I for an explanation of the return and reason codes. For return code 20 reason code 0, IDC3009I says
RETURN CODE 20 Explanation: There is insufficient space in the catalog to perform the requested update or addition.
The catalog cannot be extended for one of the following reasons:
- There is no more space on the volume on which the catalog resides
- The maximum number of extents has been reached
- The catalog has reached the 4GB limit
- There is not enough contiguous space on the volume (required when the catalog's secondary allocation is defined in tracks).
Programmer Response: Scratch unneeded data sets from the volume. Delete all unnecessary entries from the catalog. The catalog may need to be reallocated and rebuilt if these steps do not resolve the space shortage.
I suggest contacting your DFSMS Administrator. I also suggest bookmarking the z/OS documentation for your version/release.