I debug my VoltDB applications under Mac OS X and regularly see this problem. The machine is synced to Apples NTP server time.euro.apple.com. On further investigations the Exception seems to match syncronisation with the NTP server:
From the console:
Initiator time moved backwards from: 1285146127863 to 1285146127260
#1285146127260-->Sep 22 10:02:07 BST 2010
My plan short term is to turn off the synchronisation to the NTP server but looking at the System log, I think this could lead to up to 50s drift per day. Are there any better solutions?
$ grep ntpd /var/log/system.log
Sep 22 10:02:06 seo01s-iMac ntpd: time reset -1.041238 s
The NTP daemon seems to only make negative adjustments if time gets more than 128ms out of sync. For a reliable NTP server and an NTP client that has a good sense of the hardware clock's drift profile, that's quite a bit.
Now I'm not an expert in how to override OS X's GUI configuration of the NTP daemon, but it seems like you could do a few things to mitigate the problem.
1. Try a different NTP server like pool.ntp.org. It might reduce the frequency of the issue, but it's probably not a full fix.
2. Figure out how to run the NTP daemon with the -x option. From the manpage, it will make the daemon resist negatively adjusting time unless the diff is over 600s. If your actual skew is over 50s a day, then it might still have to make negative adjustments.
3. Improve the drift profile. I forget how to do this, but google should be helpful.
4. All or some combination of the above.
If your mac is a laptop and it is frequently moving locations and/or connecting and disconnecting from the network, this may be a tough problem to solve, short of disabling NTP as you have already tried.
Finally, if you do turn off NTP, you can always run ntpdate as a one-off whenever you're not running VoltDB.