[Android Q&A, Help & Troubleshooting] DMcCunney:
Installing apps to an external card

According to the FAQ, the maximum size is 32GB. That's what I put in mine,

(The FAQ may be inaccurate - the on device manual claims you can't use an external keyboard, and must use an on screen model. It's wrong. I got an adapter for Female USB->male microUSB, plugged in my Logitech Portable USB keyboard, and it worked. A Logitech entry appeared in Settings to let me specify keyboard layout. That's intended for national character sets for foreign languages, and the default layout was fine.)

Note that you cannot install apps to an external card without some hacking and software help.

I just finished doing that. The problem is that SD cards come formatted as FAT32. The FAT file system does not support the permissions and other things needed to have apps live on the card. You can use a card to store data, but not apps. (It's where my eBooks, audio files and videos live.)

To install apps on the external card, you must do several things.

First, the device must be rooted. It cannot be done if you don't have root.

Second, you must repartition the external SD card. This can be done from Linux with GPartEd, or GPartEd from a live CD, or a windows tool like the freeware MiniTool Partition manager. (I used MiniTool for convenience.)

I ejected the card from the tablet, and plugged it into the Windows machine with a microSD adapter, and did the work from Windows. I carved out a 2GB partition on the card, and formatted it with the Linux ext4 file system, which Android uses. I also marked the partition as Primary (required), and changed the partition ID to indicate the partition had a Linux file system instead of FAT32.

Third, replace the card in the A727, and reboot the device. When it reboots it can see the additional partition on the external card.

For software, I used a freeware app from the Play Store called Link2SD. If you have partitioned the external card and created a Linux file system on a partition, Link2SD can move apps to it, and create symbolic links to the new location so Android will see and load the app from the card.

You don't install apps directly to the card. You install them to internal storage, and move them to the card with Link2SD after installation.

Some apps will let you partially relocate them to the 1GB internal sdcard. Whether that can be done depends on the app and if the developers set it up to permit that. You can check by long-pressing on the app icon and selecting App Info. That will bring up a screen indicating the space the app takes, and if it can me moved there will be a "Move to card" option.

Link2SD is useful for the ones that can't be moved to the internal card.

In my case, the worst offenders were the various Google apps. Only the Google+ app can be relocated to the internal card, and they are generally large. I had reached the point where several would not successfully update because there was insufficient application storage to permit it, and had to find things to remove to free space.

With Link2SD, I could relocate them to the external card. Free application storage on my tablet jumped from 88MB to 292MB thus far, and there are more things I might be able to move.

There is an open source app called Mount2SD that does similar things. I had both installed, but couldn't get Mount2SD to work, while Link2SD did, so I used it.

First, root your device. Then, happy hacking.

______

Dennis