Out of Extents (or nearly)
In the diagram above P is a primary request extent, and S is a secondary request extent.
Due to the severe fragmention each request for space has been satisfied with 5 extents, the maximum possible per request.
Notice that the last extent bucket in the Format 3 DSCB is unused as this situation is likely to yield an SB37 ABEND when trying to satisfy
the third request for secondary allocation is attempted.
The next page describes the effect of using the CONTIG sub-operand of SPACE.