In the agent's install directory, BladeLogic will store transaction logs and files in a set transactions directory. These transactions allow for rolling back jobs. Files overwritten by the job, for instance, are stored in this transactions directory. The issue here is that some clients may not have adequate space on the volume or even on the system that the agent is installed...especially over time. Ideally, the agent transactions directory should be configurable to an alternate location (enhancement request #29421).
In the meantime, we have an nsh script that can be scheduled and run to cleanup this folder on target servers. It takes one parameter, days_back, which tells the script the number of days of transactions back from today (i.e., when you run the script) to keep. So if I say 30, it will remove all transactions older than 30 days.
The big gotcha, of course, is that BL will no longer have rollback information for jobs whose transactions are deleted, and thus will fail if you try to rollback.
Like any new script, test thoroughly before using in production.
A possible version 2 of this script will archive/move, rather than delete, old transactions.
Special thanks to Stathy Touloumis for writing the core logic of this script (and on short notice).