On 2018-07-11, Zbigniew Jędrzejewski-Szmek <zbyszek(a)in.waw.pl> wrote:
The effects of fsync are impossible to see unless you hard-reboot
the
machine.
Are you sure non-fsynced changes are are guaranteed to be visible on
block cache level? E.g. if you mix read/write and mmaped I/O from
different processes?
I wonder if it wouldn't be more robust to use nspawn's
syscall filter
to filter the fsync calls.
Can the syscall filter fake a success of the syscall return value?
Correctly written applications check fsync() return value and forward
the error.
-- Petr