I have Gentoo installed as guest OS. I have hardware clock synced with host system, but the clock of OS tend to be wrong after suspend.
The only solution I find out is run
hwclock -s frequently via cron.
Any better method?
VMware tools might do this for you, but Gentoo is not in the guest compatibility list so it may not work, or may take a lot of effort to get working.
You could use ntp to keep the clock up to date, or schedule ntpdate to run. I am not sure if these are better methods than hwclock -s.
One thing you may want to avoid is a method that simply changes the clock time - that will result in cron jobs being skipped. ntp speeds up the clock to get to the correct time. ntpdate changes the clock time.
Can't rely on TSC http://en.wikipedia.org/wiki/Time_Stamp_Counter
Try hpet or acpi_pm
Plus kernel command line option clocksource=hpet (set inside boot loader configuration.)
See Documentation/kernel-parameters.txt in Linux source.
I built a new Gentoo VM guest on VMware Fusion 3.1.3 on another Macbook and installed open-vm-tools which is in portage. I had to unmask two packages but they built OK.
The /usr/bin/vmtoolsd process keeps the guest clock in sync with the host clock. It does some other housekeeping too. Admittedly it may take a short while for it to bring the clock into sync but it does it for me.
To get accelerated I/O etc. you want to activate these kernel options too:
They don't require a "tools" package as the upstream kernel contains those drivers by default now. The open-vm-tools-kmod package contains additional driver modules. My config file is visible in this gist:
I didn't actually read this wiki entry, I just installed the packages and configured the startup scripts and kernel options myself but it might be useful: