Improve very slow library scans on Jellyfin 10.11 / 12 on spinning media

I’ve been trying to upgrade from 10.10 to 10.11 for a while now, as the Android TV app keeps nagging me, and every attempt ended with impossibly long library scan times.

After some thorough investigation, it appeared that a Home Videos type collection causes unending scan (yet to be solved), but also that Jellyfin does a lot of writes to the config directory (either database or metadata or both). Mine’s on spinning media part of a ZFS pool. I tried a few performance tuning options, such as testing the config dir with recordsize (similar to block size) of 4K, 8K, 64K, 128K and library scans fell from 30-40 minutes down to 8-13min with 4K-64K. The ZFS tuning wiki suggest 64K recordsize with LZ4 compression for SQLite workloads such as Jellyfin. That seems to work as well as 4K and 8K but likely is faster when reading thumbnails and such.

Note that upgrading to 12-rc3, which is supposed to speed up library scans did not improve scan times for me. Optimizing config/database write speed did. I cross-checked the culprit by experimenting with moving the config dir to NVMe and RAM. Both of those got the scan times down to 8-9 minutes compared to the optimized spinning media’s 12-13.

So if you had upgraded (or about to) to 10.11 your library scans are (about to get) dog slow and your Jellyfin’s config dir resides on spinning media, optimize its write performance for SQLite.

Isn’t it ironic that you post this meme along with complex instructions to fixing a problem in jellyfin?

Also doesn’t jellyfin not support remote streaming?

It’s a nonsensical statement. Jellyfin is accessed through a website. You’re responsible for routing to it.

It’s a very sensical statement. I’m not exposing a whole ass website on my own network just for remote viewing. With plex you don’t need to do that.

Yes you do. It just does it for you including handling SSL.

Inside the network you do, but not for remote access outside the network.

Outside the network you still have to open your server to allow plex cloud to access it and potentially tunnel your traffic through plex.tv if a direct connection doesn’t work. This happens automatically but it does happen

With Jellyfin you just have to supply your own relay, like Tailscale or wireguard, which does require more setup but is completely free, means that you can stop your media traffic from being funneled through services that harvest your data (which plex absolutely does), and doesn’t go to shit if plex.tv goes down

This happens automatically but it does happen

And that’s the key, it happens automatically and it just works. With jellyfin you have to expose the web server to the internet, or point an app to something else exposed on the internet. With plex you don’t. If you don’t want to (or can’t) a direct connection from your server to their servers, then their servers to your device is established. No VPNs, no reverse proxies, no port forwarding, nothing exposed to the rest of the internet.

What I’m praying for is for Jellyfin to add a tailscale like direct peer to peer system. They can skip the backup funneling traffic through their servers. But just have something that coordinates a direct connection with just basic NAT.

It is literally a cloudflare tunnel/ tailscale type thing but contained in the app. The only real difference is that it is bundled in the app, so less setup and in exchange, Plex itself is free to harvest all of your data.