Clock drift in Fedora 36, but not in Ubuntu / RISC-V

[vielmetti]

I'm puzzled by this, and I don't think I have enough details to debug it quite yet.

I have a Fedora 36 virtual machine running on a MacBook Air (M1) with lima 0.11.1, and a second one on the same machine running the RISC-V emulated Ubuntu.

The RISC-V Ubuntu seems to keep acceptably good time, but on the Fedora 36 I'm seeing these messages in dmesg and that VM is about 17 minutes behind.

[186496.089907] systemd-journald[117362]: Time jumped backwards, rotating.

This seems perhaps related to #850 which reports clock skew with Alpine Linux (under colima).

[jandubois]

I think this is a duplicated of #850.

The time jump would be due to the Lima guestagent adjusting the time when it detects a drift of more than 2 seconds compared to the RTC.

However, this same mechanism should make it impossible to fall 17min behind. Maybe the RTC approach was wrong and is also subject to drift compared to the host clock?

[vielmetti]

Is there a way to read out RTC directly on the system or the guest from a command line, and does the guest agent log its drift adjustments? I see some logrus() calls, but I don't know where that log file would be kept.