posted in Selfhosted

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.

Edited ⁨⁨Jul⁩ ⁨30⁩, ⁨2026⁩, ⁨20:26⁩⁩enPage

Replying to @⁨MaggiWuerze@feddit.org⁩

Jellyfin doesn’t open up your network unless you specifically allow remote access exactly like Plex. The only difference is Jellyfin doesn’t have the encrypted tunnel built in- you need to know it needs it and add it yourself.

Plex has had bugs that allowed remote access into your home’s Plex server. nvd.nist.gov/vuln/detail/CVE-2025-34158

nvd.nist.govNVD - CVE-2025-34158

Replying to @⁨Blue_Morpho@lemmy.world⁩

Having an https connection doesn’t do shit if the Backend is insecure. The issue with exposing Jellyfin are not man in the middle attacks, but badly managed access controls and unsecured endpoints.

Thede issues and the unwillingness of the devs to fix them because they are hellbent on keeping a maximum of client compatibility is what makes it hard to trust the overall security of the project.

That’s why basically everyone, including the devs, says to not do that and instead rely on a vpn to mitigate security risks.

Replying to @⁨GoatSynagogue@lemmy.world⁩

You obviously don’t use Plex to claim it doesn’t need an open port for remote access:

…plex.tv/…/201543147-what-network-ports-do-i-need…

I already posted a CVE that allowed hackers access to a Plex server running at home.

Plex SupportWhat network ports do I need to allow through my firewall?Note: This article is discussing ports in the local firewall of the computer running Plex Media Server. This is not...

Replying to @⁨GoatSynagogue@lemmy.world⁩

I quoted Plex documentation where it explains in detail that you need port 32400 OPEN for remote access. support.plex.tv/…/200289506-remote-access/

I linked the CVE but here is the plain language version because you didn’t read what I linked:

howtogeek.com/over-300k-plex-servers-are-still-vu…

"The flaw has been assigned a CVSS score of 10.0, the highest possible level of severity. This score indicates that the vulnerability can be exploited remotely over the internet, is easy to execute, and requires no authentication or interaction from the server’s owner. A successful attack could result in a total loss of confidentiality, integrity, and availability. An attacker could access, modify, or delete a user’s private media files, or even disable the entire Plex server. "

What the fuck is wrong with you?

Plex SupportRemote Streaming (Setting Up Remote Access)Enable access to your Plex Media Server from outside your local network so that you can reach it when away...

Replying to @⁨Blue_Morpho@lemmy.world⁩

You clearly don’t understand how Plex and port forwarding work if you think that is in any way the same as opening a port to the Internet for everyone to hit jellyfin with zero security on it.

The CVE has been exploited zero times that we know of, and at worst they can delete your media files and Plex server. It’s never been reported of happening, and we have no idea how difficult it is to do - but because it hasn’t happened, it’s probably extremely hard and requires a chain of very unlikely things to have happened first.

Replying to @⁨fuckwit_mcbumcrumble@lemmy.dbzer0.com⁩

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

Replying to an earlier post

You can do the exact same thing with Plex, you just don’t need to since automatic remote streaming is built in. In fact, the article’s solution is literally Tailscale.

You can also bypass plex authentication on any ip range you choose, so if you add your local network and plex’s auth service goes down, it’s no big deal.

XDAI bypassed Plex's remote streaming paywall with one free toolYour Plex server can stream remotely for free if you know about this mesh VPN trick

Replying to @⁨ragebutt@lemmy.dbzer0.com⁩

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.

Replying to @⁨fuckwit_mcbumcrumble@lemmy.dbzer0.com⁩

They won’t do that because it’s expensive and free software generally doesn’t have the budget to do this

I don’t know why you think the “just works” is any different from tunneling with a service. Your server is still opened to the internet through upnp with direct connections and through a tunnel to plex.tv when a direct connection is not possible. In fact plex is inherently less secure because their infra is both the encryption endpoint (as opposed to your client with Jellyfin and Tailscale or whatever) and their infra has been vulnerable in the past (like the massive breach in 2022).

Jellyfin with something like nginx and a vpn is open to the internet, yes, but a service that tunnels (like wireguard, Tailscale) bypasses this issue and it’s up to you to set it up as to your level of comfort

Plex is just easier but as with all things tech (especially those infected with VC dollars) “ease” translates to less secure and far more likely to exploit your data

Replying to @⁨ragebutt@lemmy.dbzer0.com⁩

I came up with a funny strategy I use to lock it down a bit. What’s exposed to the internet for me is Apache2 reverse proxy. The proxy is locked down to reject all connections EXCEPT for the ones coming from a special subdomain which is something like a 64-character long random string. This prevents pretty any unwanted connections. Obviously the special subdomain must remain as secret as a shared password among the Jellyfin users. It works for trusted users.

What I want ideally is an “authenticated firewall.” OpenWrt rejecting all connections on the open port except for an allowlist of IPs. Then there must be a system where users can authenticate and their IP is added to the allowlist. I haven’t found an off-the-shelf solution like this but I’ll make it some day. Too bad I figured this random string subdomain trick cause it seems good enough for now. :D

Replying to @⁨avidamoeba@lemmy.ca⁩

Give it a look on dnsdumpster.com or similar. Your dns records are inherently public, so anyone that works out the domain can work out the subdomain. In fact there are plenty of tools that just scan every domain/subdomain they can find.

DNSDumpster.comDNSDumpster - Find & lookup dns records for recon & researchFree domain research tool to discover hosts related to a domain. Find visible hosts from the attackers perspective for Red and Blue Teams.

Replying to @⁨KairuByte@lemmy.dbzer0.com⁩

Thanks for the pointer. Checked, tried a couple others - they don’t know about it. They have some other non-random DNS records. AFAIK they can absolutely find it if they scan for all domains, but it’ll take forever if the name is randomly-generated and sufficiently long. Someone has to be determined to spend the resources. This doesn’t guard against that but against bots trying to fuck with the service at the port. I could move it to a wildcard though. There’s an overlap with another subdomain (they’re actually sub-subdomains and the first sub is common) but I could move that.

Replying to @⁨fuckwit_mcbumcrumble@lemmy.dbzer0.com⁩

It absolutely does but you have to do it yourself, they dont accept any liability for doing that and nor should they, so if you dont know how to do it with at least the minimal level of safety and security and accept that risk yourself then you really shouldn’t try. Ideally you would only do it via a private VPN to trusted users.

Plex has some features built in to make just opening the port reasonably safe, though I’d still recommend against that. They also have a reasonably secure account verification system, and the software itself has proven to be somewhat safe.

Jellyfin has very little security built in and is not intended to be public facing, it also has the double edged sword of being open source, so you could read through all the code and pick it apart for flaws and exploits if you wanted to and we all just trust that when exploits or flaws are found they are reported properly.

JF is great but you are on your own if you want to make it available via WAN.

Replying to @⁨GoatSynagogue@lemmy.world⁩

I think you’ve fundamentally misunderstood some of their communication.

There’s the issue I described earlier where it is possible to stream files unauthenticated if you know the folder structure on the video. The devs have responded that they won’t fix this. Outside of streaming content, there’s no other access through this mean. github.com/jellyfin/jellyfin/issues/1501

Then there’s the release of 10.11.7 that fixed a number of security issues. github.com/jellyfin/jellyfin/releases/…/v10.11.7 with no major security issues since then. And all the issues were privilagr escalation for a normal user account on jellyfin. So the attacker would already needed to have an account on your server, and only the data that jellyfin could see was at risk, nothing escaped contagion so to say.

They also officially support a reverse proxy set up: jellyfin.org/docs/general/…/reverse-proxy/.

I have no idea where you’ve got the idea where they themselves claim it’s unsecure to open it to the internet. Of course there’s always a risk associated with exposing something, but jellyfin doesn’t pose any larger risk than anything else you might publish.

Describe the bug This is sort of a roadmap/implementation/opinion question, but will Jellyfin keep video streams completely unauthenticated as they are for the foreseeable future? It was somewhat s...GitHubVideo streams completely unauthenticated · Issue #1501 · jellyfin/jellyfinDescribe the bug This is sort of a roadmap/implementation/opinion question, but will Jellyfin keep video streams completely unauthenticated as they are for the foreseeable future? It was somewhat s...by DMouse10462

Replying to @⁨HereIAm@lemmy.world⁩

Accessing files unauthenticated……the devs explicitly say they won’t fix it…… and you think that’s not a huge security hole? Software with something like that marked as “won’t fix” is a giant no-no for me. If they’re ok with that, their software should be nowhere near an internet connection.

The person with a fundamental misunderstanding is you.

Replying to @⁨GoatSynagogue@lemmy.world⁩

Hi, could you tell me why? I mean, I think I understand the basics of the risk of brute force attacks. My mitigation for the admin account is, not to allow login outside the local network. Users are allowed from anywhere, as my family uses the library. Also my service (there are others) are routed through NGINX.

Do you have tips for external users using, for example, a VPN only for specific addresses / IPs? At least that was an idea I had, but didn’t got got around to dig for solutions.

Thanks in advance.

Replying to @⁨avidamoeba@lemmy.ca⁩

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.

Replying to @⁨zr0@lemmy.dbzer0.com⁩

Thanks for looking into it. As far as I read they moved to an ORM with 10.11 as a prereq to supporting other db engines. I’m guessing the db connection code would be undergoing major changes when they do that so I wouldn’t rewrite the current implementation. I’d either follow that work and help them get it right or rework the implementation after they’re done. We’ll just suffer through the mean time. 😄

Replying to @⁨avidamoeba@lemmy.ca⁩

Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I’ve seen in this thread:

Fewer Letters More Letters CGNAT Carrier-Grade NAT DNS Domain Name Service/System Git Popular version control system, primarily for code ISP Internet Service Provider NAT Network Address Translation NVMe Non-Volatile Memory Express interface for mass storage Plex Brand of media server package SATA Serial AT Attachment interface for mass storage SSD Solid State Drive mass storage UDP User Datagram Protocol, for real-time communications VPN Virtual Private Network ZFS Solaris/Linux filesystem focusing on data integrity

12 acronyms in this thread; the most compressed thread commented on today has 13 acronyms.

[Thread #66 for this comm, first seen 31st Jul 2026, 00:40] [FAQ] [Full list] [Contact] [Source code]

Hachyderm.ioImran Nazar ~ عمران نزر (@Two9A@hachyderm.io)2.8K Posts, 301 Following, 262 Followers · Front-end #typescript developer and general keyboard tapper; author of Internet RFC 7168 (Hypertext Coffeepot Control Protocol for teapots); occasional plumber, more than occasional #c64 #retrocomputing enthusiast, terrible at classical #piano. Header photo is a verdant scene looking over the landscape near Buxton, England, taken from a single-track country road.

Replying to @⁨Strit@lemmy.linuxuserspace.show⁩

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.

Replying to @⁨avidamoeba@lemmy.ca⁩

If you use folders a lot, the library will get faster with v12 github.com/jellyfin/jellyfin/issues/15141

OP said this didn’t improve their situation though.

Description of the bug After successfully upgrading to version 10.11.0, me and others users have noticed that when you have to load folders in a library, the loading of the library page becomes dra...GitHubPerformance - Folders make library loading drastically slower in 10.11.0 · Issue #15141 · jellyfin/jellyfinDescription of the bug After successfully upgrading to version 10.11.0, me and others users have noticed that when you have to load folders in a library, the loading of the library page becomes dra...by User-PDB3D

Replying to @⁨Carol2852@discuss.tchncs.de⁩

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).

Replying to @⁨ragingHungryPanda@piefed.keyboardvagabond.com⁩

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.

Replying to @⁨cryptix@discuss.tchncs.de⁩

Jellyfin expects you to actually host it yourself, instead of baking in a proxy and selling you the service.

There are plenty of free subdomain providers, and let’s encrypt gives out free certs.

If you’re not hosting through a VPN you should consider those a requirement so you’re not sending an unencrypted password to your jellyfin instance over the internet. Regardless of your ISP situation…

Replying to @⁨Faceman2K23@discuss.tchncs.de⁩

This is true but it’s nice to have the whole app, data and database in one place, going together, snapshotted together, “backupable” together. It’s slower for sure. That said it can be reasonably fast with a large pool (more disks). With the magic of SSD cache, database reads fly and reads are the majority of the loads in my heads. In the future I would put root on ZFS as well and either do SSD cache or have root on ZFS SSD pool that gets send/recved regularly onto the spinning pool so it’s easy to restore when needed.