OMEGAMON IMS has offered a very nice newly re-designed Application Trace Facility (ATF) for some time now. There is some maintenance that has come out in the past couple months that you may want to be aware of if you use OMEGAMON IMS.
I've stumbled onto this a couple times recently. If you've applied UA65930 you may or may not have noticed that if you were automatically starting up ATF at OMEGAMON startup, it may not be starting anymore. If you see an error message like this, OIJ251: CSO SIZE: xxxxxxxx GREATER THAN 64 BIT STORAGE: xxxxxxxx you may have stumbled onto this issue.
What this means is there are knobs in OMEGAMON IMS you need to be aware of that control things like how many transactions ATF may keep in memory, and how much storage the facility may use.
Here's a link that explains it in a little more detail:
Here's a link to the related APAR: