On 10/11/06, John Summerfield <[EMAIL PROTECTED]> wrote:
If the underlying hardware clock keeps good time, does the Linux clock actually drift?
On zSeries, the Linux system clock was supposed to be locked to the TOD (apart from the corrections by ntpd). That's because the TOD is used to measure time rather than count by interrupts (similar to the instruction counter in Intel CPUs). There have been bugs that caused Linux system clock to drop behind. I believe those were/are bugs.
Let's ignore DST as a separate issue.
Yes indeed. NTP is based on UTC which does not have time changes. The glibc locale define when your local clock is yanked forward or backward, and by how much. The way that works is real cute. These are files created by my test that wrote a new file every second: 30 2004-10-31 02:59:58.000000000 +0200 file61.tmp 30 2004-10-31 02:59:59.000000000 +0200 file62.tmp 29 2004-10-31 02:00:00.000000000 +0100 file63.tmp 29 2004-10-31 02:00:01.000000000 +0100 file64.tmp I'm surprised we did not bring this up before in the thread ;-) ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
