I am experiencing horrible performance with my nfs datastores in esxi, as expected when reading about the sync options. Now I have a question, if say I create a second nfs share, which is not used as an esxi mount, and mount this in a vm with NO sync, what would the possible consequences be for me? The performance is around 20 times better with no sync... The way I understand it, is that ZFS also syncs, so it should be fine. On a power loss the most I could imagine is that a single file which is writing atm. could be corrupted. This I assume is the same that we would expect if writing something with samba and experience a power loss.