My first post here at Veeam forums, so be gentle

We are very intereseted in Veeam, one big reason for this is "Instant VM Recovery"
If this really works it comes close to replacing an expnsive HA solution in our environment.
We plan to have a few NAS for stroring the backups and offcuase run the VM from the same NAS if there is a need for "Instant VM Recovery".
Since we are not familiar with Veeam, we wonder what fileystem needs to be on the NAS.
The reason this question arises is that Veeam backup server/proxy, needs to see this filesytem, and write to it, at the same(later) time the ESX host also need to see this file system so it can "mount" the VM files?
I guess we run into the same issue if wee want to use SureBackup.
So, what is the typical setup when using NAS and you plan to use Instant VM Recovery.
iSCSI, NFS.. what filesystem?
If this is already dicussed here, please point me in the right direction, i did not find it when i searched.
Thanx
Espen