Some time past and I like to pick up this old topic as I recently did some DR testing with XOSTOR as well. My pool is HA enabled and the VM configured to restart.
I started with some basic vm migration and reboot of hosts. Disk will sync and resync fine. I was not able to cause an error performing those tasks.
c33fd8d0-aaa8-40a5-9a08-8196ef90304f-image.png
94fb646c-5fb2-4561-80de-d51ef503bf70-image.png
I further removed power from the active host to cause a serious outage. The VM became unavailable. XOSTOR shortly after enabled the disk on the other node and restarted my vm automatically.
05a6c6a9-4981-4b43-8c6c-07cd2b7734d1-image.png
I verified that no data was lost. Made some file modifications within the vm and powered up the other node again. It re-joined the pool and synced disk no problem.
4c521301-d237-4354-93a5-b1b721ccef97-image.png
Its pretty much the exact same behavior we are used to have with vSAN. I'm very happy with this result !!
I hope this helps someone that is looking for this kind of setup.
Stefan