SFS will anyhow scan its logs to check what it has to do at restart (rollback/foward recovery from last checkpoint/xxx), and this not only after the clock change,but maybe also a bit later if it were to abend.
Maybe you can execute the procedure "Replacing Both File Pool Log Minidisks", chapter 7 in the SFS admin book. I guess in this order: - shut SFS down cleanly - change the HW clock - reIPL but do NOT start SFS - replace the logs 2009/10/18 Shimon Lebowitz <[email protected]> > Kris wrote: > > > As far as I understand, CICS uses the local time in its logs, not UTC > (and > > that's the reason that CICS must be kept down). So keeping CICS down for > > an hour will be enough. What the HW clock is doesn't matter for CICS. > > So I would need CICS to be down 1 hour *IF* I was > changing "local time". Since the procedure I described > was to start at local-8PM and remain at local-8PM > (by changing the HW *and* the offset), I should be > able to restart CICS immediately. > > > But, if you'd have DB2, that will use UTC -or more exact: the HW clock- > in > > its logs (just like SFS), playing with the HW clock may mean you have to > > keep them down ... > > Oh!! SFS uses HW time?! So will I need to leave all my SFS > servers down for 3 hours? (In my planned procedure, local time > remains 8PM, but HW clock changes from 9PM [with offset -0100] > to 6PM [with offset +0200] ). > > If I did an orderly shutdown of VM, would I still need > to worry about SFS? If each server was shut down, > aren't all outstanding transactions ended? Why would the > logging be a problem? > > > Thank you for any clarification! > Shimon > > > > > My question is: If I now > > > -- shut down my system at > > > 8PM local time, when our hardware clock is 9PM > > > (according to our current settings: the hardware is still set > > > to local summer time), > > > -- and I change the hardware clock to > > > 6PM (UTC, 2 hours behind standard local, and 3 behind > > > summer local), > > > -- and set the VM timezone to 'standard local' at UTC+2, > > > which will be 8PM > > > ----> what will happen with CICS? > > > Do I need to have it down for 3 hours (since the HW clock went > > > from 9PM to 6PM) ?? > > > Or can I start it up immediately (since the VM local time > > > stayed 8PM) ? > > > > > -- > ************************************************************************ > Shimon Lebowitz mailto:[email protected] > VM System Programmer . > Israel Police National HQ. > Jerusalem, Israel phone: +972 2 542-9877 fax: 542-9308 > ************************************************************************ > -- Kris Buelens, IBM Belgium, VM customer support
