Hello,
my first post ever here, so I just have to use the opportunity to say what an amazing product unRaid is
However, I too have the samme issue as OP. Its seems that my poor little SSD has written around 50TB of data on it. (Bought June 2019, only used for unRaid).
I was for a long time on version 6.7, but after upgrading directly to 6.8.3, I started getting a lot of notifications about excess heat on my SSD and saw that something wrote massively to the drive.
I checked every docker app, turned them off - but still had the issue.
(At the same time as upgrading the unRaid version, I also did extend my docker image to have more space, since I had to stop the array/boot the server anyways.)
I almost never got notifications about excess heat on 6.7. (EDIT: as a result of the massive writing of course) This led me to googling and finding this post.
I implemented the solution described here, and it worked! No more constant write and heat notifications on my SSD drive( BTRFS, encrypted).
A bit scared to boot the server now, since I know rc.docker will reset. (Will it however boot my docker apps as normal, even without the symlink?)