Normally, when you change journal receivers, you continue the sequence number of journal entries. When the sequence number becomes very large, consider resetting the sequence to start the numbering at 1. You can reset the sequence number only when all changes are forced to auxiliary storage for all journaled objects and commitment control is not active for the journal. Resetting the sequence number has no effect on how the new journal receiver is named.
Some conditions prevent you from resetting the sequence number, such as an active commit cycle. If the system cannot reset the sequence number, you receive message CPF7018.
If you use system journal-receiver management for a journal and RCVSIZOPT(*MAXOPT3) is not specified, the sequence number for the journal is reset to 1 whenever you restart the system or vary on the independent disk pool containing the journal. When you restart the system or vary on an independent disk pool, the system performs the change journal operation for every journal on the system or disk pool that specifies system journal-receiver management. The operation that the system performs is equivalent to CHGJRN JRN(xxx) JRNRCV(*GEN) SEQOPT(*RESET). The sequence number is not reset if journal entries exist that are needed for commitment control IPL recovery. When RCVSIZOPT(*MAXOPT3) is specified, the sequence number is only reset when you restart your system or vary on an independent disk pool if it is approaching the maximum value.
If you specify RCVSIZOPT(*MAXOPT1), RCVSIZOPT(*MAXOPT2), or RCVSIZOPT(*SYSDFT) for the journal to which you attached the receiver, the maximum sequence number is 9 999 999 999. If you specify RCVSIZOPT(*MAXOPT3), the maximum sequence number is 18 446 744 073 709 551 600. If you do not specify a receiver-size option, the maximum sequence number is 2 147 483 136. If these numbers are reached, journaling stops for that journal. Whenever you change journal receivers, the system tells you what the starting sequence number is through message CPF7019. Also, when you are approaching the sequence number limit, CPF7019 is additionally sent to the QSYSOPR message queue every time you change journal receivers.
The system sends a warning message (CPI70E7) to the journal's message queue when the sequence number exceeds 2 147 000 000. If you specified RCVSIZOPT(*MAXOPT1), RCVSIZOPT(*MAXOPT2), or RCVSIZOPT(*SYSDFT) for the journal that you attached the receiver to, the system sends the warning message when the sequence number exceeds 9 900 000 000. If you specified RCVSIZOPT(*MAXOPT3), the system sends the warning message when the sequence number exceeds 18 446 644 000 000 000 000. If you use system change-journal management support (MNGRCV(*SYSTEM)) for the journal, the system attempts to change the journal and reset the sequence number one time. The message is sent only if the attempt is not successful.
To reset the sequence numbers for journal entries proceed as follows:
To change the sequence number with the Change Journal (CHGJRN) command, specify the SEQOPT(*RESET) parameter.