Settings when running two servers using the same media folder

[Maxi2b]

Is there a specific purpose for running the secondary server? Do you intend to keep it as a backup, or do you intend to use it along with your main server?
Also, are both servers running the exact same hardware?

You could do what I'm doing. I have a two servers. On both, Jellyfin runs in a container with the media and Jellyfin config folders outside of the containers.
Daily, my main server copies the media and config folders onto the secondary server (using an rsync task). Since the Jellyfin config folder is relatively small, this can be transferred to the 2nd server within a minute.
Before the transfer, I have a script run to turn off the Jellyfin container on the 2nd server, then a second script run to turn it back on around 10 minutes later. I figured leaving around 10 minutes of time is more than enough time to allow for the config folder to be copied to the destination in its entirety on a 1Gbps network link.

So when my 2nd server starts Jellyfin up, that Jellyfin instance will have an exact copy of my main server. If I make changes on it, it will only hold for a day. The rsync task I use is set to delete anything that's not on the main server (basically an exact copy after each transfer). Each day, it will get updated with whatever is on my main Jellyfin server.

Also, since both my servers have different hardware, I edited one of the xml files for playback to modify which settings to use for transcoding, then made a script replace that exact xml file on the 2nd server so that after each daily rsync task, the 2nd server will still have its necessary playback settings. I also did something similar with some of the scheduled task files so that the 2nd server doesn't run any background tasks (since the main server does all that work).

I use two identical NASes as backup-servers for computers and each other. One at my place one at my mother's place. I want run a second Jellyfin server at my mothers place so she can watch the media as well. So I guess my intend is to have two separate Jellyfin servers that just use the same media folder.
For me it sounds like with your setup even the watch time would get reset on the second server, which wouldn't be ideal for my situation.

[Efficient_Good_5784]

I want run a second Jellyfin server at my mothers place so she can watch the media as well.

I understand that not everyone has access to decent internet where they live, so this sounds like a solution to that problem. Most people would be thinking about how to make their Jellyfin server accessible over the internet.

For me it sounds like with your setup even the watch time would get reset on the second server, which wouldn't be ideal for my situation.

Everything recommended to you in this thread will have the 2nd server never save watch times. In fact with how Jellyfin works, all your users are expected to use the same server. There is no code to handle multiple servers to mix their server data.

If you want your parent(s) to be able to save their watch status/time, they will either need access to your main server, or you need to allow them to run their own Jellyfin instance.

If you leave them with their own Jellyfin install, you can set it up to auto scan when new media is added to a library. So your main server could only work on transferring over the media, and the Jellyfin service on their end would take care of the rest. Just make sure to create a non-admin account for your family members so that they don't mess with the server.

[abpjf]

I have this exact same scenario (2 Jellyfin servers using the exact same NAS libraries, 1 server for "outside" use and another for "inside" use) and have never run into a problem, with syncing data or watch times or what have you. Basic config:

1. As most have already stated, designate one server as the "master" - ALL data management is done via this server

2. The "slave" server should have ALL scraping/update functions DISABLED (as in, it should never automatically update libraries on media detection, no metadata scrapers set up EXCEPT for "use local metadata" only, etc), all user accounts (except your own) on that slave server should be not-Admin ("read only" as others have stated)

3. Whenever you add / remove / otherwise update library content, do so via the Master server; make any info/matching/corrections BEFORE even thinking about the Slave server

4. WAIT as long as needed (honestly, if you have no reason to do an 'immediate' update sync on the Slave, then don't) for any scans/refreshes/etc to complete on the Master - at least 10 mins minimum

5. ONLY THEN do you have the Slave server "scan for new" - it will correctly 'sync' content with the Master

ALL my users on the Slave server have no problem with watch progress, continue-from, etc