Found that below dataset contain more than 1 extent. How to enlarge the dataset
Dataset Name XT
Release : 12.1
CA 7 delivers sample JCL in library CAL2JCL member AL2DBLXX to help you resize the CA Datacom LXX log File LXX file.
You will not lose data, because you will spill it before resizing (in step 2 above).
Below is the link about sizing the LXX: