We had almost 8000 QACXxxxxxx files in our tmp directory in the IFS on our System i Enterprise server. They didn’t seem to be causing any harm, but they were definitely taking up space.
According to Oracle (WARNING: you will need access to Oracle’s customer support site), these files are temporary and should be cleaned by the system when a UBE completes processing. So far, since I have been monitoring, the UBEs are completing successfully, but the QACX files are remaining in IFS.
According to the Oracle doc, these files can be deleted…preferably when E1 services are down to ensure that you do not delete something the system is using.