Sorry for the little explanatory title, but what really happened was this:
Today while browsing through my library stored on the server where I ran the OMV (HP Proliant, G2020, 12Gb ram, 2x4Tb + 1Tb disk) from my device connected to tv (android box running Kodi), I forced Kodi to update the list files and after a few minutes, nothing new was displayed in the list. When I access the Transmission interface that runs on the server, all the files that were in "seed" mode showed the "file not found" error. I accessed through my laptop the folders that were available by SMB and ALL the main folders were there, only its contents had disappeared. I accessed the server via SSH and confirmed that nothing existed anymore. I rebooted the server and now the ZFS pool that occupied the 2 4Tb disks was with all available clean space ...
I started in the OMV logs something strange and the thing that caught my attention was the record of several attempts of my android box to index the shared folders that were denied by the server.
Does anyone know of a history like this? Do you have any idea what might have happened and if you have any way to take back the "missing" files? And no, I did not have the snapshot active at the time of the disaster ...
PS: In folders not usually accessed, where I left the backup of some documents, only some of its contents disappeared, keeping older files, which were there for more than 1 year (my server would have 2 years running 24/7 without serious interruptions ).