[Miscellaneous Android Development] Bait-Fish:
Unfortunately, I have more questions than answers regarding Root External 2 Internal SD swapping the storage. It is not fully successful on my Nabi 2, apparently not useful. Hopefully it is just me doing something wrong and someone who has it working successfully can chime in and point out the error of my ways. I was working on this yesterday and typing it up today. Here is what I was already going to post.

I've tested [unsuccessfully] Root External 2 Internal SD on my Nabi 2. It does something, but not what I'm expecting. I expected it to essentially swap the /mnt/sdcard (internal) and /mnt/sdcard2 (external). A big part of the reason I expect this is due to a link crediting original work toward Root External 2 Internal SD by mattiadj in this thread. The video in the OP clearly demonstrates that the internal and external storage swap, seen in Android's Settings>Storage.

Here is what I've observed on my Nabi 2. Using the settings e2950 posted previously, my external SD mirrors the internal SD, as observed in the systems's Settings>Storage. But, the external SD "disappears," as does its capacity, gone, missing. Using Root Explorer, the results are the same. /mnt/sdcard and /mnt/sdcard2 have the same contents as far as I can tell.

I further attempted to find where the external SD was disappearing to by creating what I will call a "tracer file" named _TrueExternal placed in the root of the original external SD (/mnt/sdcard2) and another named _TrueInternal on the root of the original internal SD (/mnt/sdcard) before activating External 2 Internal SD [Clicking the button External>Internal]. This was attempted with both a 16GB micro SD (FAT32) card and a 64GB micro SD (FAT32) card to rule out differences there.

After attempting the swap, my tracer file _TrueExternal was nowhere to be found using Root Explorer to search everything from the root directory and below. Searching manually myself comes up nil as well. It does find four _TrueInternal tracer files after the swap, when it was only in two places before swapping.

My test results are as follow. Booting directly into Parent or Nabi mode doesn't appear to make a difference.

Before changes, stock rooted Nabi 2:

Android Settings>Storage:

Internal Storage: (usage graph showing nearly full)

Total: 4.49GB

Available: 278MB

Settings>Storage:

SD Card:

Total: 59.46GB

Available: 59.45GB

Tracer files found in these locations searching with Root Explorer.

/data/media/_TrueInternal

/mnt/sdcard/_TrueInternal

/mnt/sdcard2/_TrueExternal

Root External 2 Internal SD settings per e2950's post, BUT, I ensured no /etc/Init.d/init.d file (deleted previously to troubleshoot).

Settings>Storage:

Internal Storage: (usage graph showing nearly full)

Total: 4.49GB

Available: 278MB

SD Card: (usage graph showing nearly full)

Total: 4.49GB

Available: 278MB

Nabi plugged into Win7(64) PC shows same result:

Internal Storage:

277 MB free of 4.49 GB

SD Card:

277 MB free of 4.49 GB

Tracer files found in these locations searching with Root Explorer.

/data/internal_sd/_TrueInternal

/data/media/_TrueInternal

/mnt/sdcard/_TrueInternal

/mnt/sdcard2/_TrueInternal

_TrueExternal file NOT found searching with RootExplorer

Stock:

Settings>Storage:

SD Card:

Total: 59.46GB

Available: 59.45GB

/data/media/_TrueInternal

/mnt/sdcard/_TrueInternal

/mnt/sdcard2/_TrueExternal

I noted in another post that the init.d that this app creates was as follows.

sleep 2
mount -o remount,rw /
mkdir -p /data/internal_sd
mount -o bind /mnt/sdcard /data/internal_sd
mount -t vfat -o umask=0000 /dev/block/vold/179:49 /mnt/sdcard
mount -o bind /data/internal_sd /mnt/sdcard2

P.S. I'm torn whether or not to dedicate a new thread to this, as others would likely see it in General.