Yesterday, all of a sudden my smartphone (a Samsung Galaxy Note N7000) started to misbehave. The first thing I noticed was that the battery was down to <15% rather early in the day. I didn't think much about it, just plugged it into the charger and forgot about it.
This morning I wanted to put it back into my pocket and noticed that it was now complaining about "Insufficient Storage Available" with the hint to uninstall some apps or widgets. Since I haven't installed anything for a while, apart from the regular updates, I thought that rather strange. Especially since there was lots of space free on the micro sd card. Of course internal storage is always at a premium so that was probably what the shortage was about. It turned out that from the 2 gb internal storage apps used 540 mb and cached data used 35 mb, so where did the other >1.3 gb go?
This answer to a stackverflow question, which interestingly enough is also about a Galaxy Note, offered the solution. Apparently some stupid app writes log files to internal storage and never deletes it. In /data/log I found more than 1500 log files, each around a megabyte in size. I guess that explains where the storage space went. Deleting these files was easy enough since I run a rooted CyanogenMod, so I could just use the installed file manager to do it. That took care of the warning.
Added 2014-12-30: There is another directory with log files in /sdcard/logs
Unfortunately that wasn’t all of it. Another error message kept popping up: “Unfortunately android keyboard (AOSP) has stopped”. I had ignored it until then because I thought it might be caused by the storage problem as well. It probably was but it wasn’t solved by freeing more storage. Even after a reboot of the phone it kept crashing so I had to investigate further. Google turned up this blog post FIXED! – Unfortunately Android Keyboard Has Stopped Solution which caught my interest because of the upper cased “FIXED” in the title. And – wonders of wonders – it actually explained the fix: Clearing cache and data of the “Android keyboard (AOSP)” and “Dictionary Provider” apps solved the issue for me.
So I could finally start assembling the bloody kitchen cabinet which turned out to be much easier than I thought.