Docker Read Only File System - RC9

Dec  9 07:28:18 OBI-WAN emhttpd: shcmd (117): /usr/local/sbin/mount_image '/mnt/INTEL1TB/docker/docker.img' /var/lib/docker 50

Is this mounted on a ZFS pool?  If so, you'd have to recreate the issue onto the cache pool.

Well the diagnostics show that currently the docker.img file is corrupt.     No obvious reason why this has happened.

And if it's not on a ZFS pool, then you're attempting to put it onto a UD drive that isn't mounted

Dec  9 07:28:16 OBI-WAN unassigned.devices: Disk with serial 'INTEL_SSDSC2KB960G8_PHYF911201UY960CGN', mountpoint 'INTEL1TB' is not set to auto mount and will not be mounted...

(this line is 2 seconds before the mount of the image and since it doesn't exist, then the docker image winds up going to RAM)

Well it's not RC9 as it appears to be also happening on RC7 (managed to downgrade).  So to that end I expect this is a localised system issue.  What I can't figure out is, why when I have a perfectly good filesystem on my SSD (checked) the BTRFS docker.img file get's errors and the system makes it to read only.  There must be something obvious I'm not understanding.

Sorry, I posted above and hadn't realised there were other posts.  Yeah it's on ZFS.  I got fed up with btrfs so changed it out has never been an issue until now.  Anyway, I'm pretty sure it's something to do with that device now that I've had some time.  I'll probably go post on the ZFS plugin page now if I need help.  Thanks everyone.

One thing to be aware of.  If I understand correctly, the version of the ZFS plugin has to match the Kernel versions used by the OS.  RC7, RC8, and RC9 all utilize different kernel versions, and the plugin has to match that.

Yeah, it's been updated to support all those versions.  ZFS is a bit tricky when it comes to understanding disk space which is where all my hesitation is.  It has about 20GB free, but I suspect that's the issue.  When you delete something on ZFS, it actually doesn't free the space right away due to the snapshots.  I expect this is my issue.