The Catalog size might be increased due to several reasons.
Prior to versions 2.7.1 the size of the CFT Catalog could not be increased dynamically and were having issues.

Error in Log:
CFTU26E CFTFILE  _ Error ( Catalog file creation error)

In Version 2.7.1

An administrator can now dynamically increase the size of the catalog using the below CFTUTIL.

CFTUTIL RECONFIG TYPE=CAT, RECNB=xxxx

Deleting and creating a new catalog is no more required. This will dynamically increase the size of the existing catalog.