When masking job is run in the Portal faced slowness in the tool and noticed that there were 150K + entries per second in the logs.
It appears that this heavy IO activity keeps tool busy and context switching becomes progressively slow and eating away the hard-disk space.
Release : 4.9.211
Component : CA Test Data Manager
Engineering fixed the issue in the version TDMWeb-126.96.36.199.zip and FastDataMasker-188.8.131.52.zip