So, I have rooted my phone (GT-i9505 with android 5.0.1) and I would like to move my WhatsApp folder to my external SD card to save 3GB on internal storage. This is what I tried so far.
EDIT: solution found
So, after all the option #2 seemed to be the right one, but it needed some tweaks to make it work. As suggested by Irfan Latif , the problem was that the mount point has to be created in a global mount namespace, otherwise other apps will not see it, so the commands to use are:
su -mm mount -o bind /data/sdext2/AppData/WhatsAppMedia /sdcard/WhatsApp/Media
But that may not be enough! It still didn't work until I made sure that the namespace of root was global. To do that I don't know any universal way, but what worked for me was going in the SuperSU app settings and uncheck the option
mount namespace separation.
That really depends on the SU app that you have installed.
Option 1: symlink
The first thing that I thought was to make a symlink, so that was the command that I used:
ln -s "/data/sdext2/AppData/WhatsAppMedia" "/sdcard/WhatsApp/Media"
I had already created a second partition on my external SD card (ext4) that is mounted in
However that returns
operation not permitted when using the terminal emulator (yes I did
su) and an error with any root file manager app that I tried.
After some research I figured out that for some reason, although
/storage/emulator/0 is in an ext partition, it is treated in a differente way so that it doesn't support symlink inside (correct me if I'm wrong).
So, onto the next thing
Option 2: mount
According to this question, the following command should mount the folder on external SD card in another folder in the internal SD card, without the need for a symlink
mount -o bind "/data/sdext2/AppData/WhatsAppMedia" "/sdcard/WhatsApp/Media"
However, while running the command doesn't return any error the folder in
/sdcard/WhatsApp/Media is still empty, so I don't really know how to handle this.
Option 3: symlink in /data/media/
I followed the instructions on this post and made the symlink in
/data/media/0 instead of storage, so using this command:
ln -s "/data/sdext2/AppData/WhatsAppMedia" "/data/media/0/WhatsApp/Media"
This time the link is created! However ...
/data/media/0/WhatsApp/Media revealed that the link was successful,
cd /sdcard/WhatsApp/Media returns a very irritating
no such file or directory and that is confirmed by the file explorer that shows an empty folder with a blank file icon.
First of all, I now discovered that I really hate android. Now, stated this, here's what I think might help doing:
- moving my sdcard files somewhere else: if the rest of the root filesystem supports symlink (which it seems like it does), I might even move the folder
/storage/emulated/0somewhere else and make a new link to it, but I don't know if that would solve the problem
That's it for now, I will update with more options when I think about them...