Looking at git history, I see this commit that makes an assertion counter to my test results: http://git.grml.org/?p=grml2usb.git;a=commit;h=7a6e10df
Previous to that commit, I did not see fsync being used. Michael: is that commit message based on experimentation? If so, perhaps neither sync approach is really sufficient, and maybe we need to implement a retry loop :/
