The differencing disk does not inflate except when there is a database write. Users have sometimes seen this grow very quickly when they had various automatic maintenance operations set up. For example, if you rebuild indexes, that will cause the entire rebuilt index to be in the diff disk.

Running substantial image modifications, and then cloning the modified image, may also cause clones to inflate. In this case, disabling database indexes just before the modification and then rebuilding them afterward may resolve this. For example:

ALTER INDEX MyIndex ON MyTable DISABLE;

UPDATE MyTable SET ... ;

ALTER INDEX MyIndex ON MyTable REBUILD;