UBIFS synchronisation questions about file create/delete

[Ronny Dierckx]

Hi,

I'm using UBIFS (git://git.infradead.org/~dedekind/ubifs-v2.6.27.git)
on an ARM device with OneNAND flash.

I've been reading the documentation, FAQ, ... about sync/fsync/fdatasync and
the
write-back buffers, but there are still some things I don't understand.

I create a file with vi, write some data in it, close it, don't call sync.
Then 
after waiting 10 minutes I cut the power. When the system is restarted, the
file is
not there anymore?! Is this normal behavior? Shouldn't there be at least
a file of 0 bytes because "UBIFS operations which change directory entries
are synchronous"?
Doesn't this mean that creating or deleting a file entry doesn't require a
sync ?

Thanks,

Ronny Dierckx