On Tue, Nov 8, 2016 at 7:52 AM, Christopher Brown <[email protected]> wrote:
> Hello Listers, > > A curious situation from Saturday night. At an acquaintances site, they > usually do a POR (no idea why and I'm afraid to ask) for the time change. > They also like to sit for an hour as they believe the DB2 logs will be > corrupted (not a DB2 user but I have my doubts about that). Anyway, the > sysprog (who is offsite) had OPS shut the machine down and he would call > back an hour later to IPL. But due to a medical issue he never did call > back or IPL the machine. So through a chain of events, the acquaintance (a > mainframer but not a sysprog) called me for help. So its now 0630 and they > are hours behind. I get them logged onto the HMC and walk them through an > IPL. During this process I am questioned about changing the time as they > do it on the HMC (what??). I tell them we don't have time (no pun > intended) to figure out why or where he usually changed the time on the HMC > and we were going to use the SET CLOCK command from the console. So a > miracle occurs and the IPL goes without incident, we set the clock, and > they start to unravel their application mess. > > > But they are now in a state I've never seen before. Local time is good, > but GMT/UTC is daylight savings time. The only thing I can come up with is > that they set local and GMT equal. And there is no prompt or timezone > parameter in the CLOCKxx parmlib member. So there're asking me what if > they IPL again and the time hasn't been changed on the HMC?? As an STP > user (the greatest thing since sliced bread) its been years since I've had > to manually do anything with changing clocks, but as I recall we never did > anything other than a SET CLOCK command. > > So if they IPL, what will the local time be? Is there a reason to change > the time on the HMC? And the only time I've ever seen GMT set is at the > TOD prompt at IPL, true? > > Doing an IPL does not affect the value of the TOD clock. That is what will set the z/OS time at IPL. So, if you ended up needing to do a SET CLOCK= (or, better SET TIMEZONE=) to get the local time correct, then if you IPL, somebody will again need to set the local time. What does a "D T" say? As an example, mine says: IEE136I LOCAL: TIME=08.10.51 DATE=2016.313 UTC: TIME=14.10.51 DATE=2016.313 If you have no timezone parameter in the CLOCK member, then the local time will be set to the "UTC" time as shown in the above message. Your client is wallowing in the deep, dark past. DB2 logs run off of the TOD clock (usually set to UTC) and pays _no_ attention to the local time. The same with IMS. CICS does pay attention to the local clock, but a simple CEMT PERFORM,RESET command will fix that right up. Or simply recycle the CICS region (likely what your client does if they run CICS<shudder>). UNIX processes are "who knows" but given what you've said, I'd think it likely the client doesn't do much with UNIX. -- Heisenberg may have been here. Unicode: http://xkcd.com/1726/ Maranatha! <>< John McKown ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
