This is a local host issue.
When using docker, we can’t see what’s happening with the host filesystem.
The best I can give you are the Linux Tips.
(for fs.inotify.max_user_watches)
I will share that my experience with BTRFS has not been favorable.
I’ve watched many Synology users lose their entire storage volume (media and PMS) due to BTRFS. IMHO, it has not proven itself to be stable
My personal choice is the one proven by enterprise servers – xfs.
It’s more robust and a heck of a lot faster.
It also scales VERY well.
FWIW: 12x 12TB HDDs, RAID 6, xfs format, pulls 2.0-2.1 GB/sec
