If the file group becomes full or if a journal output error occurs, OpenTP1 performs swapping. The user must always provide a swappable standby file group so that swapping can always be performed.

If swapping of a journal file group is to be performed, OpenTP1 checks the status in the memory and looks for a swappable standby file group. When OpenTP1 searches the memory for a file group and cannot find any swappable file group, it reads the status from the journal file of the file group being opened and updates the status in the memory to the status in the file. OpenTP1 then checks the status in the memory again and looks for a swappable standby file group. If OpenTP1 still cannot find any file group, it terminates abnormally.

When OpenTP1 terminates abnormally because there was no swappable file group, it can be restarted by unloading the file group with the jnlunlfg command or by correcting the erroneous file group. If OpenTP1 still cannot be started, the user must specify a new file group with ONL specified in the system journal service definition and then must restart OpenTP1.