serverAppConfigs/serverAppConfigs-docs/Dankserver/Media Metadata View.md

type, title, description, tags, timestamp

type	title	description	tags	timestamp
reference	Media Metadata View	The SSD-backed overlay the two media servers read and write: shape, guards, commands, laws, rollback.	dankserver media-server jellyfin plex storage	2026-10-30T00:00:00Z

Media Metadata View

/var/lib/media-meta/view is an OverlayFS merge of the media library: the RAID6 array below, a directory on the NVMe above. It exists so Jellyfin can write Kodi-format sidecars (movie.nfo, tvshow.nfo, episode.nfo, artwork) that Plex can read. Sidecar metadata is only useful sitting next to the media file, and the array is read-only and slow — so the media bytes stay there and the writes land on SSD. One tree to both servers, one copy of the media.

The mount point is not a volume and holds nothing while unmounted. It sits inside /var/lib/media-meta so that layers, kernel bookkeeping, the reap trash and the merged door are one directory — and so the mount table grows no new /mnt entry next to the array.

Not deployed on Dankserver — verified 2026-10-31. scripts/media-view.sh status answers view: /var/lib/media-meta/view NOT MOUNTED, /var/lib/media-meta does not exist, and the installed quadlets under ~/.config/containers/systemd/ still carry the pre-view binds — /mnt/entropy:/data:ro for Jellyfin, /mnt/entropy:/mnt/entropy:ro for Plex. Everything below is the shape git describes, not the shape the servers run. The cutover is an ordinary deploy: deploy.sh dankserver --service jellyfin|plex runs ensure_media_view (install then verify) before it restarts the container, so it must not be fired through the middle of a library scan. Until that deploy lands there is no upper layer, so no relayout can leave ghost metadata and reap has nothing to do — media-apply.py prints that follow-up only when the view really is a mountpoint.

Shape

Item	Value
Lower layer	/mnt/entropy — the RAID6 array, source of truth, never written
Upper layer	/var/lib/media-meta/upper — NVMe; every write lands here
Work dir	/var/lib/media-meta/work — overlayfs internals, same filesystem
Mount point	/var/lib/media-meta/view — the merged tree both servers bind
Unit (repo)	dankserver/host/systemd/media-meta-view.mount — the source of truth
Unit (host)	var-lib-media\x2dmeta-view.mount — systemd names a mount unit after its escaped path (- becomes \x2d); media-view.sh install writes the repo file under that name
Installer	scripts/media-view.sh — plan / install / verify / status / reap
Written by	Jellyfin only (Plex binds read-only); nothing else in the fleet touches it

Both consumers guard the view with UnitConfigItem=ConditionPathIsMountPoint=/var/lib/media-meta/view, and scripts/deploy.sh dankserver --service jellyfin|plex calls media-view.sh install + verify before it restarts either container.

Consumer	Bind	Mode	Why that path
Jellyfin	/var/lib/media-meta/view:/data	rw	It is the metadata writer; its sidecars become SSD bytes
Plex	/var/lib/media-meta/view:/mnt/entropy	ro	Every path in the PMS database was recorded as /mnt/entropy/...; only the HOST side of the bind moved, so its database still resolves

Putting the sidecars inside Plex's reach is not the same as making Plex use them: a library parses .nfo only with its Local media information agent enabled, and this change touches no library setting.

Commands

scripts/media-view.sh plan              # print the resolved shape, touch nothing
sudo scripts/media-view.sh install      # create dirs, install the unit, mount, enable
scripts/media-view.sh verify            # is the view really the overlay? (deploy gate)
scripts/media-view.sh status            # mount options + upper-layer size/file count
scripts/media-view.sh reap              # list ghost metadata (media moved, sidecars left)
sudo scripts/media-view.sh reap --apply # move ghosts to the SSD trash, never delete

--upper-base DIR and --lower DIR relocate the layers for plan and reap; the defaults are the host values above.

Laws

• The upper layer must sit on non-rotational storage. install and verify refuse via lsblk -dno ROTA if the upper base lives on the array: an overlay whose upper is the spinners is the original problem with extra steps, and it silently turns every metadata write back into a seek.
• Never mount the view over an unmounted lower. RequiresMountsFor=/mnt/entropy plus the container ConditionPathIsMountPoint guards: an empty lowerdir presents an empty library as truth, and a media scan would then clear the database of everything. systemd does not create a mount point, so install creates view itself; without it the mount simply fails.
• Never delete through the view. A delete writes an overlayfs whiteout (.wh.<name>) in the upper layer, which hides the array's copy without removing it — the file reappears the moment the view is unmounted, and the upper layer now carries a landmine. Deletions belong on the raw path (/mnt/entropy), which the relayout tool already treats as the only writer. reap refuses to remove whiteouts and only warns about them.
• A relayout must be followed by reap. Renames happen on the raw path, so sidecars the view already wrote stay at the old coordinates: a ghost folder the servers browse and find nothing in. reap lists upper-layer directories with no counterpart below and moves them (with their subtree) into a dated .AGENTTRASH/ under the SSD base. It is recursive and file-safe: a sidecar that exists only above is normal, so only directories are candidates.
• File-watcher events do not cross the overlay. Plex's NFO agent and Jellyfin's real-time monitor see inotify events for writes that land in the upper layer, not for changes on the array underneath. After any relayout or externally-written metadata, trigger a library refresh — see Media Relayout for the refresh procedure.

Failure signatures

Symptom	Meaning
jellyfin.service / plex.service show ConditionPathIsMountPoint=... was not met and stay inactive	The view is not mounted. Do not start them anyway: scripts/media-view.sh install, then verify.
Jellyfin log: Read-only file system : '/data/Movies/…/movie.nfo'	The container is binding the raw array, not the view — the quadlet drifted back or the view is gone. media-view.sh status.
A folder appears in a media server with artwork/.nfo but no video	Ghost metadata from a relayout. media-view.sh reap.
verify prints refused: …/view is not a mountpoint	A plain directory is sitting where the overlay belongs. That is the fail-closed guard working; install on the box.
systemctl status finds no such unit	Look under the escaped name, var-lib-media\x2dmeta-view.mount, not the repo file name.

Rollback

Revert the commit that pointed the two quadlets at the view and re-deploy both services — they bind /mnt/entropy read-only again, which is the pre-view shape. The NVMe upper layer can stay: nothing reads it once the binds are back, and it holds no state either server needs. Unmounting alone (systemctl stop 'var-lib-media\x2dmeta-view.mount') is safe while no container binds it, and the array is never modified by any of this.

Links

• Jellyfin — the metadata writer; its data layout section.
• Plex — the read-only consumer; in-place bind-mount history.
• Media Relayout — the tool that moves media on the raw path and the reason reap exists.
• Entropy Volume — the array underneath.