As the title suggests my 16GB Shield prompted me today that it's storage space was critically low (~ 250MB of internal left), I thought this was slightly odd considering I keep a 64GB Micro SD as adoptable storage and thought i moved over any app that'd grow substantially onto that when I first got the device.

I first deleted a few games I'd recently installed (Portal, Geometry wars 3 etc.) to see if that'd fix the issue, no dice.

I use SPMC to manage my media and know that with all the metadata the SPMC folder can get pretty big, inspecting it with Xplore showed it was around 7GB on the SD card, the settings menu stated 6.7GB of internal use so I guess the SD card is adopted. That's perfectly fine considering that I keep a large library (on an NAS so that's not the cause either). Aerial dream, an app I use for my screensaver was found using 6GB of space for it's cache which is excessive but nothing in comparison to the absolutely massive 33GB thumbnail file hidden in my DCIM folder.

I have no idea what program created it, maybe it was SPMC storing files or Plex or just an app misbehaving but I felt like it shouldn't be there, I deleted it, uninstalled Aerial Dream and rebooted the device. Same low storage prompt popped up again and suddenly the interface felt so much more sluggish. shit.

At this point I backed up SPMC to my NAS and tried clearing the cache in the settings, the cache refused to be cleared (tried before and after force closing SPMC) so I tried uninstalling. The uninstall worked and so I rebooted, still sluggish. The settings app was now crashing occasionally. At this point I tried to reinstall SPMC thinking that I could try keeping it's size small, got greeted with the error that there wasn't enough space to install SPMC even when I had literally just uninstalled a much larger version of it . It seems that whatever was hogging the internal space wasn't SPMC at all.

At this point I gave up and performed a factory reset, I'm not getting the low storage warning which is nice. Currently in the process of restoring my SPMC backup, no closer to understanding what caused this.