nfs issues

we move 12 KVM's from drbd to nfs storage.

now we have storage unstability.

for instance:
1 - after migrations we have had 4 corrupt file systems and 2 systems with broken mysql tables.

2- when I tried to add a 2-nd nfs mount [ to test using ssd drives ] , the 2-nd mount in pve shows all the 1-st mount's info. from size to content.

I can supply a lot more detail .

I've a question - is anyone using nfs + drbd and having no issues? If not I'll assume we've something basic wrong with our set up.