Re: Time Change

On 16-Feb-2012 09:47 , rob@xxxxxxxxx wrote:

I also tend to believe that few 5.1 shops (especially those STILL
running 5.1) would be using journalling.

As I said, *irrespective* of any user jobs, there may be impacts to the OS and any date\time dependent activity. Jounaling is not limited to user jobs. If the system is not powered off, journaling as a feature persists within any system job [or subsystem monitor job], just as might any date\time dependent activity such as an event to be signaled at\by a certain time which with typical implementation transpires when exceeded but for which an implementation may re-establish the time-specific event given time moving backward.

The system should be powered down for the time lost due to moving the time backwards, setting the time during a manual IPL while bringing the system back up; i.e. time is reset before the OS and user jobs could be impacted... while the system is starting.

There are very few if any situations for which the OS would care about the time moving forward; as I implied, time-related events are signaled for the event having been passed, not for the specific time having been noticed by the OS. Unless there is concern for the gap in time for "users" [applications], then there is little reason to power down the system when moving the time forward; the OS and time-dependent code will be much more tolerant when time only moves forward.

Regards, Chuck