Zee-Unraid

Just to close my topic off:
 
I found that I had a sata expansion card/ controller that wasn't compatible with Unraid, and could have been, at least partially responsible for the drive failure and corruption - as my cache drive was connected through this expansion card. From a "casual Unraid user" perspective, and considering that Unraid is designed to make complicated activities simpler - controller/ expansion card compatibility/ awareness, (that this is even a "thing"), really should be highlighted when users are adding drives through the Unraid UI. Or some sort of single pop up on installation/ acknowledgement. 
 
It might prevent people from having issues, reduce forum posts for help, and overall help the planet by preventing drive failures. It should be seriously considered from an environmental perspective, if nothing else.
 
Finding it in a forum post (hardware compatibility), after the event, is pretty soul destroying and one of those eye-roll moments once I checked and could see my expansion card indeed was not compatible.
 
Yes, it's my fault for not checking the forums; however please consider doing more on the Unraid side to at least bring this to people's attention somewhere between installation, drive addition in OS, and drive errors/ failure. E.g., when drive errors are first detected, perhaps a pop up/ alert asking "do you have an expansion card/ controller installed, check this post on compatibility". 
 
I'm not sure what's possible, but please if there is anything you can do on your side to prevent other users encountering issues and reducing environmental waste, please kindly consider it. 
 
Anyway, after I'd installed my new cache drive with the new controller; I found that I had some data from the array appdata, which wasn't visible to me on the array whilst the cache drive was offline, that reappeared with the new cache installed and it recovered most of my containers. I've still got some rebuilding and work to do, but at least I had some things top start from. 
 
Thank you regardless, @JorgeB, I very much appreciated your quick responses and no-nonsense help. You have hugely helped me here and for that I am very grateful. Please do consider/ discuss with the Unraid team if there can be anything done in this area. Wishing you all the best. Take care.
 
Link to my specific resolution and learnings around sata expansion cards/ controllers: