For those who don’t go to the VMware forums (another ‘communities’ based vendor website) often, there was finally a VMware employee who somewhat unofficially acknowledged the issue of running ESXi on SD cards, specifically with vSphere 7U2. I say U2 because v7 and v7U1c, of which I both have run on DELL IDSDMs, runs flawlessly; and has for the past year.
To read a little more on the issue, you can review the VMware Communities post here. The issue, it seems, has to do with their newly formatted boot partitions. But honestly, I think the mishap (Hosts disconnecting/hanging) is mostly due to a new vmkusb driver. VMW is currently working on a fix, though they’re really recommending orgs to start using ‘high-performance’ storage (i.e. disks) for the boot device moving forward. All that to say is, if you haven’t upgrade to 7U2, I recommend not to. If you’re running your boot on disk, I think you’ll be fine. Otherwise, hold off.
One of the Veeam Vanguards, Luciano Patrao, did a nice little post on the issue & his experience. You can read his article here.