On Fri, 2 Mar 2012 19:31:55 -0600, Joel C. Ewing wrote:

>On 03/02/2012 06:44 PM, Charles Mills wrote:
>> And the answer from those who know is
>>
>> "It happened during the POR last Thursday and we're talking with IBM to
>> figure out why a POR would do that to us."
>>
>> Thanks all for your patience with YATQ (yet another time question).
>>
>> Charles
>>
>
>In absence of sysplex timer or the like, the processor TOD clock is set
>only at POR and is set based on the HMC clock, which may in turn sync
>once a day with the SE clock.  If you don't have any procedure to sync
>the HMC/SE clocks to UTC or verify they are reasonably accurate when you
>know a POR is imminent, odds are they have drifted from reality and a
>POR will propagate that error to the processor TOD clock, which in turn
>propagates to all LPAR TOD clocks as they are activated.  It would seem
>your operators must be setting local time explicitly at IPL (rather than
>using a fixed offset from TOD), or the error would have been more
>obvious after the IPL.My recollection is it has worked this way ever
>since IBM mainframes have had HMCs for control.
> 
And the fun part is, I think it takes another POR to get things all
synched up.

Does anyone else see anything wrong with this picture?

-- gii

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