Hi,
The failed disk is out of the problem, it's an internal RAID 1 (on different controller) that did not disturb the server at all (failed few days before my vsan issues).
Thanks for the two links you provided, but I don't see best recommended way to do it.
So in "conclusion", if my hba card accept hot add, I should not have any issues hot adding disks to production running ESXis, there is no need to put host in maintenance mode or any other kind of precaution procedure ?
About stretched cluster, should I claim new disks once all disks have been added in all hosts in both sites or I can expand site 1 and expand site 2 later ?