How to Avoid Media Metadata Rewrites During Library Maintenance

Eva Wong

IceWhale author

Eva Wong is the Technical Writer and resident tinkerer at ZimaSpace. A lifelong geek with a passion for homelabs and open-source software, she specializes in translating complex technical concepts into accessible, hands-on guides. Eva believes that self-hosting should be fun, not intimidating. Through her tutorials, she empowers the community to demystify hardware setups, from building their first NAS to mastering Docker containers.

How to Avoid Media Metadata Rewrites During Library Maintenance - Zima Store Online

Media metadata rewrites are easiest to avoid when curated fields and artwork are backed by durable sources before library-wide maintenance begins.

A scan, provider refresh, database cleanup, path move, or server upgrade can touch very different layers of a media library. Before maintenance, identify which titles, posters, collections, NFO files, and manually edited fields are authoritative; lock what the server supports locking, back up local sidecars and artwork, and run the least destructive refresh mode on one test item. Do not choose “replace all metadata” just because the maintenance task happens to involve the whole library.

Inventory Which Metadata Is Curated Before Maintenance

Choose a representative set of movies and episodes and record custom titles, sort names, provider IDs, collections, posters, backdrops, editions, and manually corrected descriptions. Note whether each value exists only in the database or also in a local NFO or artwork file.

A current Jellyfin metadata guide recommends lock fields you curated before broad metadata work.

If you cannot identify which values are intentional, do not start a replace-all refresh. First export or screenshot a small audit set so you can detect an unwanted rewrite instead of noticing it weeks later.

Back Up NFO Files and Local Artwork as Durable Sources

When the library uses local NFO files, posters, or backgrounds as authoritative metadata, copy them with the media or include them in the maintenance backup. Verify timestamps and checksums for a few samples.

Jellyfin supports NFO files as local metadata and can save metadata back into those files when the NFO saver is enabled.

Do not assume a database backup alone preserves every manually managed sidecar. Conversely, do not assume the NFO is authoritative if the library has only ever stored edits inside the server database.

Prefer Local Artwork When Poster Stability Matters

For posters or backdrops that must survive provider changes, store the chosen image using the media server’s supported local naming convention and back it up with the media library.

Plexopedia shows that local posters resist provider changes by keeping artwork as a durable local asset.

Test one title before rolling the convention across the library. Local artwork improves reproducibility, but it also creates files that backup, sync, and permissions policies must preserve.

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Use the Least Destructive Refresh Mode

Distinguish a normal library scan, metadata refresh, replace-all metadata operation, and replace-existing-images option. Maintenance that only changes storage paths or database indexes rarely requires replacing every field and image.

An Emby troubleshooting case illustrates how replace-all can overwrite artwork during a manual refresh.

Start with “scan for new or updated files” or the platform’s narrow equivalent when that meets the goal. Escalate to a destructive refresh only for items whose metadata is deliberately being rebuilt.

Check the Source of Truth Before Writing Back to Media Folders

If several applications share the same media tree, decide which one is allowed to write NFO files, artwork, or tags. Two servers writing the same sidecars can turn routine maintenance into a cross-application metadata conflict.

Firecore’s metadata guidance shows that artwork can be overridden deliberately at the client and library layer.

Keep one durable writer for shared sidecars when possible, or make the media mount read-only for applications that only need to consume files. The goal is a clear source of truth, not the largest possible number of metadata writers.

Run Maintenance on a Small Test Library First

Create a temporary library or select a small folder containing custom artwork, local NFO files, collections, an edited title, and an ordinary untouched item. Run the exact planned maintenance action there first.

Plex documents supported local assets follow naming rules so a test library can verify that durable local assets are still being read after maintenance.

Compare the test items before and after the scan, refresh, path change, or upgrade. The maintenance policy is safe only when curated fields stay stable and intended provider updates still work. The related ZimaSpace article on custom posters reverting after refresh is the recovery branch if curated artwork has already changed.

Frequently Asked Questions

Does a normal library scan always rewrite metadata?

No. Scan and refresh modes differ, and behavior depends on the server, metadata sources, and options selected. Test the exact maintenance action instead of treating every scan as replace-all.

Should media folders be read-only during maintenance?

Read-only mounts can protect source files and sidecars when the server does not need to write there, but they can also block intentional NFO or artwork saving. Choose the boundary from your source-of-truth policy.