Video preview thumbnail extraction using massive amounts of storage after upgrade

[MikaelKW 7]

Hi,

On 13.12.2025 i upgraded Emby from version 4.8.11.0 to 4.9.1.90. After that the "Video preview thumbnail extraction" task has been going non stop, and my C drive is about to run out of space. 

Before the upgrade, the metadata folder in AppData\Roaming\Emby-Server\programdata used 37 GB of space, with a total of 52 689 files. After the upgrade it is so far using 201.5 GB and rising, with a total of 53 054. I have not changed a single setting in Emby since the upgrade.

Why is this, and is it possible to run some sort of cleanup to delete old/unused metadata?

[Luke 42077]

Hi there, please attach the Emby server log from when the problem occurred:

How to Report a Problem

Thanks!