I have switched from PA 4.0 beta 4.4.2 KK to CM11 nightlies.After restoring all of my apps, I noticed I had only 800 mb internal storage left.Then I scanned my internal storage with app "Disk usage"
It showed 1.8 GB taken by "system storage".I can't check what files are included in "system storage" with that program, it also doesn't give me an option to delete the system storage.I have checked several places for duplicated files using ES file explorer, also used a few apps to look for app leftovers.But nothing, I still have 1.8 GB taken by system somehow and I have faced this issue before.
I don't have enough space in external SD card to backup my internal storage and then format it.This issue gets quite annoying as I like trying different ROMs out.
I have wiped /system, /data and /cache before flashing CM11.The only solution to this issue I have found so far is formatting /data and /data/media.
This had happened to me before but it was back when CM 10.2 nightlies were released for first time.I had switched to CM 10.2 from CM 10.1 and had a low storage notification after using CM 10.2 for like a week.
It's really random and I don't really know what's causing it, has anybody faced the same issue?
Note : I'm aware some files can get stuck in /storage/ or similiar locations when switching between ROMs.But I'm pretty sure this isn't the case as I checked every folder that has some connection to internal sd card.