After we rebooted one of our servers (RHEL), we noticed that it would hang when entering GRUB. The problem was the countdown in GRUB (Booting in 5... 4......) was not counting down, and was stuck at ...
I started ntpdate running every night as a cronjob (on two servers). And every morning I have an email telling me the outcome. On one server it's correcting by about 0.8 seconds every day, which seems ...