RetroFedImprove very slow library scans on Jellyfin 10.11 / 12 on spinning media
Avid Amoeba
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.
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Isn’t it ironic that you post this meme along with complex instructions to fixing a problem in jellyfin?
With great power come great .. uuh .. :D
Also the meme is just bait so you read abt the problem and see if you need to solve it for your setup.
complications 😅
Complications, yes!
Yeah but tell me about this tool for Plex remote streaming…
It’s a wrapper called jellyfin
No, I said remote…
Anyone using jellyfin should not be exposing it to the public internet.
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.
I access it via the app on my LG TV with WebOS, so not technically a website but yeah, over the network via an API at least 👍
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.
You don’t need to do that with jellyfin either. It includes the website for convenience, but you can just disable it or completely remove it and have just the server.
How do you communicate with the server outside of your network? You’d still need to expose those ports directly to the internet right? (excluding VPNs/reverse proxy etc)
I mean, if you put restrictions on the requirement sure. At that point it kinda becomes a loaded question though.
If you remove the restriction, just use a cloudflare tunnel.
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
Let’scrypt and port forward. Sprinkle on some free ddns with a sync script/job to keep ddns pointing to your real public IP. Can even roll in some headscale if you’re feeling adventurous
Jellyfin does support remote streaming and it doesnt have to be through the web ui.
You just use a VPN
I don’t have any issues with jellyfin and remote streaming?
I run the DB on the SSD and media on the hdds and haven’t had any issues, but I don’t have a huge library though. However, things are generally speedy. I thought the higher record sizes were recommended for media, not the DB? but if it worked for you, that’s good
64K is generally small recordsize. For media they recommend 1M. My db was sitting on the default 128K recordsize and perforned fine on 10.10. It doesn’t matter much for reads because ZFS keeps it in RAM and if it gets evicted it goes into SSD cache (l2arc). But for writes the cache wouldn’t help unless I disable sync which risks data loss. I don’t think 10.10 did much writes during lib scan so write perf only mattered when something changed.
How large is the database? Because there is a way to fully load SQLite into memory, which would speed everything up drastically for a scan. At the end of the scan, you could just write back everything to the disk, then it is just one blob of sequential write, which is fast enough on spinning rust.
Interesting, I figured people would use MySQL instead if possible.
600MB. Would that require changes to Jellyfin? They’re on the path to introducing Postgres support.
I just checked the code and unfortunately, they do not support loading the SQLite file into memory yet. Even worse, the change would be substantially. It appears they currently abuse the database connection a bit. They basically create a new connection for each operation. This does not matter if you can read/write in parallel, but that’s only the case with NVMe and certain drivers. So all SATA (SSD and HDD) suffer from the current mechanic. So just loading it into memory is not going to solve the issue. Jellyfin needs to change architecturally, so that a database connection is reused. I don’t know why or who implemented the current logic, but it is clearly done by someone not understanding how databases work.
Depending on the mood and time, I will come up with a solution that is solid. For now, you are stuck with the current logic.
If you use folders a lot, the library will get faster with v12 https://github.com/jellyfin/jellyfin/issues/15141
OP said this didn’t improve their situation though.
Not sure if this is the problem I was hitting with my Home Videos library type. It’s got directories with YouTube videos. I tried re-adding it in 12-rc3, which was released a month after the nightly mentioned in the issue thread. Still couldn’t complete. I ended up re-adding the media as Shows library. Works okay with the directory structure I have.
The write performance was recorded without the problematic library (deleted).
I’ve had initial scans take hours and scans afterwards usually also take some minutes. Why do you think that is an unreasonable amount of time to check all entries for updated metadata?
unending != 40 minutes.
That would be reasonable. I did repeated rescans and only counted subsequent rescans. For me the initial scan after upgrade took a bit more but not hours. Subsequent scans took less. E.g. 20min -> 13min for write-optimized filesystem. So that’s reasonable, although 10.10 was way faster. Library scans are expected to get faster in 13 according to some Github threads I read.
When I had the broken Home Videos library I waited 3 days for the initial scan to complete and it did not. Repeated rescans did not seem to complete although I didn’t wait 3 days for them. I’m not taking into account those scan times. Something was wrong with this library type on 10.11 and/or my media. Worked fine on 10.10.
Fair. I have never had a Home Video library, so I don’t know how those are scanned or what they are looking for other than embedded metadata. But yes, sounds like that library type has some issues.
Thanks, will take a look a my setup
Hey not bad for the developer…he vibe coded it right
Just the desktop client. Not the server.
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I’ve seen in this thread:
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Doesn’t jellyfin need a static IP.
No.
Static IP for what? As long as you know the ip address of your jellyfin server you can connect to it. A static IP is just good to have for ease of remembering, using your own domain (not that you can’t do it with Dynamic addresses) or if you are integrating other services with it. This applies to any service you host.
Most ISP connection are behind CGNAT(ipv4), and in case of ipv6 to have a secure connection wouldn’t that require SSL certificate and a domain?
You could use tailscale or netbird. Alternatively, you can use a dynamic DNS provider which usually provide free subdomains, if you don’t want to pay for a domain. And even with all of that, Jellyfin doesn’t require HTTPS, although there may be clients that do (make sure you’re behind a VPN in this case).
I have Pangolin setup on a VPS so I and my family can access it externally. It “bypasses” my router’s firewall. Tailscale was a stupid solution because a lot of people will be using it and I don’t want to maintain another service and be tech support for their tailscsle client. So the only thing I did to restrict access was by geoblocking.