I have a VM for source code building and running unittest.
The data in it is not critical generally. So I use "cache=unsafe" for it.
But I find that sometimes, I wish that I can force the data sync, for example
when a big project is finished to build.
A method I am using is to shutdown the VM and
I think that "cache=unsafe" option it only allows writing data to be
included in host's disk cache behaviour.
Assuming this, if I'm not wrong, when you flush host's disk cache you
are already syncing the pending writings from Qemu.
To flush at VM hosting level to disk:
$ sync
Remember that a V
