I have a GT-I9195 running Lollipop 5.1.1 (currently PAC-ROM) which in theory has 8GB of internal memory. However, I can't seem to track down what exactly has happened to all that space. With a paltry 100 or so apps (including system essentials) installed, the phone starts reporting it's out of space until I move apps to the external MicroSD card. The problem persisted even through the custom ROM installation and subsequent recent ROM update as well as a few factory resets/cache wipes/etc. It's been an issue for nearly 8 months now, and periodically I've trawled the Internet for suggestions and clues but without making any real progress.
It seems to me as if a large chunk of space on the phone's memory is simply inaccessible and unused. Is this possible? How can I delve deeper into what's going on?
I've included the output of a df command in terminal emulator below. I notice that there seem to be duplicates of the internal memory /storage/emulated/0 and /storage/emulated/legacy (though I think one is just an alias of the other), and that they are both the same reported size as /data.
Storage Analyser reports 541.93MB of that 5.3GB is used by accessible files and 3.59GB used by "android/inaccessible files". This adds up to the 4.1GB which df claims is in use, but I can't understand what that 3.59GB is when every app which can be put on the external SD card is already on it, and I thought that the /system partition contained the OS itself and was not included in /data?
I've tried to get ES File Explorer to do its SD card analyst trick on the /data folder but without success, so it's not easy to probe it and find out how big each subfolder is.
I'd really like to get to the bottom of this... can anyone offer a suggestion as to what to try next?
Edit: also of interest to me is that I do have more than a gigabyte of space on the internal storage (/storage/emulated/0), but this is apparently unavailable for installing apps on. It holds DCIM and other random storagey things, and naturally freeing up space here doesn't allow me to install any more apps on the phone memory.
Filesystem Size Used Free Blksize
/dev 663.7M 48.0K 663.6M 4096
/sys/fs/cgroup 663.7M 0.0K 663.7M 4096
/mnt/asec 663.7M 0.0K 663.7M 4096
/mnt/asec/org.mrpdaemon.android.encdroid-2 6.0M 4.8M 1.2M 4096
/mnt/asec/flipboard.app-2 9.0M 7.4M 1.6M 4096
/mnt/asec/com.netflix.mediaclient-2 33.1M 31.9M 1.2M 4096
/mnt/asec/com.tecarta.bible-2 17.0M 15.3M 1.7M 4096
/mnt/asec/com.pisanu.scrabblechecker-2 4.0M 2.7M 1.2M 4096
/mnt/asec/com.shazam.android-1 27.1M 25.5M 1.6M 4096
/mnt/asec/com.hutchison3g.planet3-2 12.0M 10.3M 1.7M 4096
/mnt/asec/com.trello-2 16.0M 14.2M 1.8M 4096
/mnt/asec/com.whatsapp-2 22.0M 20.4M 1.7M 4096
/mnt/asec/com.audioaddict.di-2 33.1M 31.1M 2.0M 4096
/mnt/asec/com.evernote-2 28.1M 26.4M 1.7M 4096
/mnt/asec/com.mxtech.videoplayer.pro-2 25.1M 23.8M 1.2M 4096
/mnt/asec/com.mxtech.ffmpeg.v7_neon-2 19.0M 17.7M 1.3M 4096
/mnt/asec/com.ideashower.readitlater.pro-2 13.0M 11.1M 1.9M 4096
/mnt/asec/com.skype.raider-2 80.3M 78.9M 1.4M 4096
/mnt/asec/com.spotify.music-2 39.1M 37.5M 1.6M 4096
/mnt/asec/org.wordpress.android-2 11.0M 9.9M 1.1M 4096
/mnt/asec/com.Slack-2 31.1M 29.3M 1.8M 4096
/mnt/asec/jackpal.androidterm-2 2.0M 604.0K 1.4M 4096
/mnt/asec/com.mictale.gpsessentials-2 15.0M 13.6M 1.4M 4096
/mnt/asec/com.adobe.reader-2 17.0M 15.7M 1.4M 4096
/mnt/obb 663.7M 0.0K 663.7M 4096
/system 1.4G 759.7M 714.5M 4096
/data 5.3G 4.1G 1.1G 4096
/cache 196.7M 4.5M 192.2M 4096
/efs 13.4M 4.2M 9.2M 4096
/persist 7.9M 4.0M 3.8M 4096
/firmware 64.0M 49.7M 14.2M 16384
/storage/emulated 663.7M 0.0K 663.7M 4096
/storage/sdcard1 59.5G 57.2G 2.2G 131072
/storage/emulated/0 5.3G 4.1G 1.1G 4096
/storage/emulated/legacy 5.3G 4.1G 1.1G 4096
Edit2: I finally did some digging in /data by manually selecting directories and querying them with ES File Explorer. Thankfully this didn't take too long before I found the main culprits:
data/media 1.45 GB
data/data 1.11 GB
data/dalvik-cache 1.17 GB
data/app 642.57 MB
data/user 1.11 GB (this appears to be a symlink of data/data)
Investigating data/media, I discovered a 1GB backup file created by ClockWordMod recovery, presumably when I first flashed the ROM. Moving it to my SD card has apparently recovered that space in /data, which is fab. This has, presumably, been the main source of my problem - that is, assuming this space is actually available for installation of apps now (not easy to check with this ROM other than by installing apps until I run out of space).
As for the other big directories: I can believe that data/app is the total size of my installed apps, and I guess there's no getting around the dalvik cache being so huge. I'd really love to dig into data/data and see what exactly is using so much space in there, but in ES File Explorer I have to manually select each folder and click properties to find out how big a directory is - a task for another time as I've been unable to find a utility to do this for me.