First things first -- don't delete files in CMOD. It's an archive system -- you can't expect it to work properly when you delete files!
Use the arsmaint command to free up space by migrating data & trimming the cache filesystem -- make sure to review the documentation so you know what each of the options are doing. (Ask questions if you don't!)
Finally, you didn't provide any error messages from the System Log -- the error messages there will explain where the error was, and you can investigate further (filesystem, TSM, etc.) to determine the root cause of the error you received in the client. You can post any error messages you receive from the System Log or TSM for us to help out some more.
-JD.