The Question is:
I have an AlphaServer ES45 Model 1B which is gaining time of 2-3 seconds/day.
We are running a high availability application which doesn't like time going
backwards so it is difficult to rectify. Over a 6 month period the clock ran
about 7 minutes fast.
Anything I've found about clock drift mentions systems losing time.
Two questions : Is there anything I can do to correct the issue without
affecting my application? What is considered normal or acceptable for the
system clock, we haven't seen it on any other Alpha (5).
The Answer is :
This and other timekeeping-related matters are discussed within the
OpenVMS Frequently Asked Questions (FAQ) documentation -- you will
want to link to an external time-base, and various options are
available. The FAQ also has details around the hardware and
software clocks, and around the relative accuracy expected.
There are two topics refered to as clock drift, one involves
lost or gained time with the most common being lost -- see the
FAQ for this -- and the other variation of the topic involves
using drifting to correct the system time. Available tools
do drift the time to correct inaccuracies, but for obvious
reasons these mechanisms will slow or speed the system clock
updates but will not cause the system time to be set back.