I have a Debian Squeeze VM that has suddenly chosen to jump it's date forwards just over a month, which seems to confuse it no end and cause it to require a hard reset (yikes!).
There is nothing unusual in the logs, except that the datestamp suddenly jumps (today back to 2005).
It's happened three times, so I don't think it's to do with the leap second issue as the last one of those was in July.
When it happened once I spent ages checking stuff but could not find anything, decided to forget it. But three times is becoming an issue on a production server.
Edits providing information requested in comments (thanks!):
I do not have control over the hypervisor, it is a hired VM.
# cat /sys/devices/system/clocksource/clocksource0/current_clocksource kvm-clock # ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== +grendel.exizten 126.96.36.199 2 u 29 64 77 14.811 1.778 1.744 *panoramix.linoc 188.8.131.52 2 u 32 64 77 19.729 -0.419 1.691 +robert.elnounch 184.108.40.206 2 u 27 64 77 17.762 0.600 1.722 -janetzki.eu 220.127.116.11 3 u 31 64 77 27.214 3.575 1.638