On Thursday 06 December 2007 17:16, Carlos E. R. wrote: > ... > > Please, remember that the system time does not use the cmos clock and > battery at all. That's a different clock altogether. Plus, the cmos > clock is running fine, I'm checking it at the moment.
"... at all ...?" I don't think this is really true, is it? When the system starts up, the Linux kernel initializes it's notion of the current time from the mainboard's CMOS clock (which, on all machines built in the past twenty years or more, is powered and running even when the computer is powered down and even disconnected from the mains; that's in part what the battery is for). Thereafter, the Linux kernel updates its time based on a timer interrupt, also generated by local hardware, of course. These timers are, as has been noted, not particularly accurate and often exhibit considerable drift over even moderate real-time intervals. But it's only after the system is up and running and, one hopes, an NTP server is contacted that the system's mediocre hardware timebase is corrected by a high-precision, high-accuracy time source (and protocol, which NTP definitely is). Likewise, if the system cannot contact an NTP server, it has a reasonable guess as to the current time, and it makes do with that. > ... > > -- > Cheers, > Carlos E. R. Randall Schulz -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
