Storage Use & Least Playback Taxing Video Format

[Duvel]

From what I understand at this point :
* You seem to have no idea of your directories' sizes and where/what your big files are.
* You suspect the cache/transcoding but you havent any log or folder size that would define it as the culprit.

You should begin to have a better view on your filesystem and to locate the biggest folder(s) on it, and for that I advise you to use ncdu
Its probably not installed by default, so install it from your package manager. on Debian based systems :

Code:

sudo apt install ncdu

then you can just throw:

Code:

sudo ncdu /

And let in run. It will scan all your folders and subfolders from the root ( as you told "/"). And then present you the tree structure with the exact size of everything sorted from biggest to smallest. And you can browse each folder until you find the culprit(s)

You can run it from the top of any subfolder which is faster but not complete, for instance :

Code:

sudo ncdu /var/logs

You can also restrict the search to files in the same filesystem with

Code:

sudo cdu -x /

After that you will have a clear idea of which folder eats the space, and if it is the cache folder or something else, and only then we can talk about the cache if it is the culprit.