Background work and server load¶
Why the server is busy when nobody watches, and why the thumbnails of a new library take hours: besides playback, the server runs work of its own (scanning libraries, fetching artwork, generating seek bar thumbnails, detecting intros and credits, analysing files). This page says how that work shares the machine with the people watching, and where to set its share.
Playback comes first¶
Background tasks draw from a share of the processor, the Global share of Admin → Server Config → Processing power: 25 % by default, 50 % to speed them up when nobody uses the server. Under Heavy tasks, one of them (new media analysis, trickplay thumbnails, intro detection, complexity classification) can be given a share of its own, which replaces the global one for that task; shares never stack. A change applies to the next item processed, no restart needed.
Whatever the share, a background task pauses while someone is watching, and resumes afterwards. This is the default: the Pause background jobs during playback switch of the Background work card in Server Config turns it off (a restart is needed). On a new library, thumbnails and intro markers therefore arrive over hours rather than minutes if the server is in use.
What runs in the background¶
| Work | What it gives | When it runs |
|---|---|---|
| Library scan | New, changed and removed files | On file changes, on schedule, at startup if enabled. See Libraries and metadata. |
| Artwork download | Posters and backdrops kept on the server, in WebP | During the scan; missing ones are retried hourly. Off: images are loaded from the internet by the browser, which some browsers block. |
| Seek bar thumbnails | The previews shown while dragging the seek bar (one image every 7 seconds) | When a title is added, and at startup for those without. Enable trickplay thumbnails in Server Config turns them off. |
| Intro and credits detection | The Skip buttons | Continuously, over every series; community timestamps are hints, not a reason to skip a title |
| Keyframe index and codec levels | Direct Play and copy without re-encoding, correct colours | Continuously, on files scanned before the information was collected |
Memory¶
Memory profile (Admin → Server Config): Low suspends plugins that are idle to save memory, and wakes them on demand. Auto (recommended) picks Low on machines with less than 3 GB of memory.
Settings read at startup¶
A few settings are read once, when the server starts: saving them stores your choice, a restart applies it. The panel says so next to them. They are the Background work card (pausing and pacing of the keyframe and codec-level passes), the Intro Skip Providers switch, and the Advanced limits of transcoding.