@Kajetan321 Ok, I think my PR made things more confusing ^^
This warning is only valid for local ISO SR, the one you create with
mkdir -p /opt/var/iso_repository
NFS ISO SR is available on all host on the same pool.
@olivierlambert can confirm if my right, and I will update the doc tomorrow
If you have already a NFS share ready, you can go to New/Storage, and add it