ntpd drifted away

[Joel Hammer]

I run ntpd on my linux boxes, using my firewall machine and
LOCAL as their only time server. The firewall synchronizes
to internet time servers.

I noticed today that one of my two clients was 20
secs fast. ntpd was running. I ran ntp-update, which
synchronized my client with the firewall time server
properly.

The question: What could cause ntpd to be that far off?
The hardware clock is only a couple of seconds off, and
this box has been up for four days. Are there log files
which would tell me the answer?

The only difference between my two linux clients is that
the bad client DOESN'T automatically run hwclock --systohc
every hour. (I just changed that.)

My second question,
1. After running hwclock --systohc
I get this when I run hwclock --show:

     Thu Mar 18 21:31:20 2004  -0.522562 seconds

What is the last number for? It changes with each hwclock --show
command.

Thanks,

Joel