IPL Method

Checklist for setting clock backwards in time: Ensure that BRMS operations have halted and none are scheduled to start. Run command DSPPFM FILE(QUSRBRM/QA1ANET2) and ensure that there are no records in the file.

1. Ensure that BRMS operations have halted and none are scheduled to start.
2. Run command DSPPFM FILE(QUSRBRM/QA1ANET2) and ensure that there are no records in the file. If there are records, then updates have not been synchronized yet. Allow the records to synchronize to all systems.
3. Ensure that no BRMS operations are occurring on any system in the network, such as saves, movement or maintenance.
4. Issue the PWRDWNSYS RESTART(*NO) command and put the system into manual mode.
5. Wait almost an hour (allow for the amount of time to IPL also) and start the IPL.
6. At the Date/Time screen, change the system time 1 hour backwards, and continue the IPL.
7. When all systems have been set, resume BRMS operations.

   Example: Clocks will be set at 2 a.m. and will be going back 1 hour. At 2 a.m., issue the PWRDWNSYS command. Wait almost one hour. Start the IPL of the system. When the system comes back up, set the clock to 2 a.m. (and whatever minutes have passed). This prevents the repetition of the 1 a.m. - 2 a.m. hour on your system, and ensures that all system journals and BRMS have no problems with duplicated time stamps or time stamps that are out of sequence with real time.

If necessary, nightly system backups (STRBKUBRM) can be run even though not all systems have been reset as long as the following are true:

1. The target system volume record is more than 1 hour old.

   Example: The last time volume X was updated was when it was moved this morning. Under these circumstances, an update for volume X from a system with a one hour earlier time will still be accepted on a system with a one hour later system time, and an update from a system with a later time will still be accepted on a system with an earlier system time because there is more than 1 hour difference between the time the save and the move were done. If the difference between the updates would be less than the 1 hour time difference on the systems, problems could result and the wrong update could be ignored.

2. The system owns plenty of scratch media (so it will not need to use DDM to 'borrow' media from other systems). During the time period that clocks are being reset, it is best to avoid operations that involve the update of a record on another system.
3. Do not run other BRMS operations, such as movement or maintenance or use WRKMEDBRM Option 2 on a volume that is not owned by the system that you are working on.
4. Resume normal BRMS operations only after all systems have been reset, and the last 1 hour of repeated time has passed on every system in the network.