I managed to corrupt some files on my 2nd hard drive due to the fact that i attached them to 2 different domU’s and booted both up. The file system was ext4. I wished that qubes at least gives me GOOD VISIBLE WARNING that i might corrupt data if the storage is already mounted in another running domain.
This might be worth having a formal bug report. Sounds like something undesireable (I didn’t even know it was possible to attach to two at the same time).