plex, sonarr, radarr and nextcloud each gain one bulk volume. Authored in the catalog and
re-rendered, never hand-edited into apps/ (render-golden: 10/10). Layout, the export change the
operator must apply, the uid analysis and the validation probes are in docs/BULK-NFS-STORAGE.md;
everything there was measured on the host over read-only SSH, not assumed.
WHAT THE LAYOUT TURNED OUT TO BE, AND WHY IT DECIDED THE DESIGN
/mnt/Storage/plex holds movies/ tv/ photos/ AND downloads/ as SIBLINGS in one dataset — so the
arrs' import source and their libraries are one filesystem on the server, and the download client's
completed folders are already named radarr/ and tv-sonarr/. The k3s arrs are joining a tree an arr
stack has been driving for a long time.
That sibling fact is the whole argument for the arrs mounting the export ROOT rather than a
subPath per directory. Sonarr and Radarr import by hardlinking or atomically renaming, both
same-filesystem operations, and to the kernel "same filesystem" means SAME MOUNT. Two subPath
mounts of one export are two mounts: link() across them returns EXDEV regardless of what the
server knows, and the arrs do not fail loudly — they degrade to copy-then-delete, rewriting every
file over NFS and destroying the seeding copy. The smallest subtree containing both tv/ and
downloads/ IS the export root, so the root mount is the MINIMAL mount that preserves hardlinks.
Least privilege bounded below by a hard requirement. The cost is stated, not hidden: sonarr can
also write /media/movies.
plex /mnt/Storage/plex -> /media ro ReadOnlyMany
sonarr /mnt/Storage/plex -> /media rw ReadWriteMany
radarr /mnt/Storage/plex -> /media rw ReadWriteMany
nextcloud /mnt/Storage/nextcloud -> /mnt/legacy-nextcloud ro ReadOnlyMany (subPath: nextcloud)
Plex is read-only because it indexes and streams; every write on that tree belongs to the arrs, and
saying so removes Plex from the set of things that can damage 8.33 T. All three media consumers use
the SAME mountPath deliberately: when qbittorrent is eventually given this export, the arrs and the
download client will already agree on absolute paths, which is the other precondition for hardlinked
imports.
*** /media AND NOT /data — A COLLISION CAUGHT WHILE RENDERING. *** The arrs' Longhorn config PVC
renders at the renderer default /data/config. A media mount at /data is mounted OVER it and MASKS
the config volume: the pod comes up with its app database shadowed by an 8 T media tree. That
discovery also exposed a SEPARATE PRE-EXISTING BUG, reported and deliberately NOT fixed here:
LinuxServer arr images run with -data=/config, so /data/config is very likely the wrong home for
that PVC and the app has been writing its EPHEMERAL layer — the exact failure catalog/plex.yaml's
mountPath comment records already having been bitten by. Plex was fixed; sonarr, radarr, qbittorrent
and jackett were not. Fixing it starts those apps from an empty config volume, so it needs its own
change with the operator present. This change does not make it worse.
UID/GID — THE FAILURE THIS TIER ALWAYS HAS
The export is sec=sys + no_root_squash, so the client's numeric uid passes through verbatim and the
server's ownership is the entire access story. The tree is 0755 owned 1000:3000, so ONLY uid 1000
can write it. LinuxServer images default to 911. Without intervention sonarr and radarr would have
mounted cleanly, gone Ready, and failed EVERY import with EACCES.
And fsGroup cannot fix that — the in-tree NFS plugin does NO ownership management, so
podSecurityContext.fsGroup is a no-op on an NFS volume. Reaching for it is how this gets
misdiagnosed. So PUID=1000/PGID=3000 are added to both arrs (PGID 3000 keeps what they write
group-readable to the live non-k3s consumers of the same export), and fsGroup: 3000 is added for
the LONGHORN config PVC only, so changing PUID does not depend on the image re-chowning /config.
plex already runs as 1000 and reads a 0755 tree; nextcloud reads as www-data. Neither needs work.
NEXTCLOUD IS MOUNTED READ-ONLY, WHICH IS A DEVIATION FROM THE BRIEF — ON EVIDENCE
The task said nextcloud writes. The dataset says otherwise: of 270 G, 267 G is config_backup/, the
rest is config/ (103 M) and config_old/ (3.4 G). There is NO data/ directory. This is the OLD
non-k3s instance's configuration plus a backup blob — an archive — and that instance is STILL LIVE
on it (exported rw to 192.168.1.6 and .5, which the operator has said must stay active). Two
Nextclouds writing one instance's config directory, each with its own database and therefore its own
oc_filecache, is unrecoverable corruption. "Do not grant more than needed" lands on ro, and ro is
the trivially reversible choice. If the intent is in fact a MIGRATION, that is a larger and more
deliberate change than a mount; the one-line flip is documented.
Read-only for nextcloud can additionally be enforced SERVER-side (only nextcloud consumes that
dataset from k3s), and the sharenfs value in the doc uses ro= for the k3s clients. The media tree
cannot: plex and the arrs may land on any node, so the server sees the same addresses for reader
and writers. Plex's ro is therefore a client-side guarantee — stated as a limitation, not left
implied.
Co-Authored-By: Claude Opus 5 <[email protected]>
jakman85andClaude Opus 5
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