After a somewhat failed system upgrade from omv 2 to omv 3 I was forced to reinstall omv and chose the current version (4.1.23-1). After extensive research in forums I learned that omv should be capable of rediscovering previously created RAIDs without bigger problems and went on to upgrade (I must point out at this point that my personal stupidity prohibited me from making backups. If I had those I would not write here). After the upgrade/reinstall of the OS the RAIDs from the old system were detected correctly but I was not able to mount them. Looking into the filesystem showed an unpleasant surprise, several ZFS headers were found on both the RAID0 as well as the RAID1 present. Using wipefs I was able to remove these ZFS headers hoping that my original EXT4 header could be found underneath that mess.
Unfortunately I had no luck.
Then, without fileystem headers I tried using testdisk and fsck to restore and rebuild the partition tables wiped. I now am at a point were my RAID0 seems to have a filesystem, as I can indeed mount it, as it can be seen in the screenshot below. Also visible is the fact that omv seems to see used disk space.
Screen Shot 2019-07-31 at 13.11.07.png
Now to my current problem. The 1.89 TiB of storage are not accessible at the moment, not through SSH and not through protocols such as SMB. When I check mounting point though SSH the partition is simply empty.
And now as a small disclaimer, I know that I am an idiot for not backing this up. But: the data stored on this RAID0 does not mean the world to me and nobody is going to die if I loose it all.
Thank you so much for your help in advance- I would not write this post if I hadn't tried everything in my limited imagination.