/mnt/extSdCard screws up various apps. How to fix?Support

  1. HippoMan

    HippoMan Well-Known Member

    I purposely purchased a large (32G) sdcard for my Galaxy Tab 2 (10.1), so I can have a lot of extra storage for certain apps.

    However, the external sdcard is named /mnt/extSdCard, while /mnt/sdcard points to a smaller, internal (non-swappable) sdcard that comes with my tablet, and I discovered that a whole slew of apps have been hard-coded to only access /mnt/sdcard as the "external sd card" without the ability to point to any other location, and this cripples my ability to use /mnt/extSdCard as extra-huge storage for some of these apps.

    I've rooted my tablet, so my first thought was to go into a terminal as root and make a symlink from /mnt/extSdCard to some subdirectory of /mnt/sdcard. This would allow all those apps to at least see the contents of the swappable sdcard when they access /mnt/sdcard. However, /mnt/sdcard and /mnt/extSdCard are both FAT32 filesystems on which symlinks are not supported.

    So I thought of another idea, but before I dive in and possibly screw up my tablet beyond repair, I want to bounce it by you folks here, to see what you think about the feasibility of the following procedure ...

    Step 1: back up /mnt/sdcard onto my desktop computer.

    Step 2: back up /mnt/extSdCard onto my desktop computer.

    Step 3: in the directory on my computer where I backed up /mnt/sdcard, copy the entire /mnt/extSdCard contents to a subdirectory called "ext". The full path name would then be /mnt/sdcard/ext, and this subdirectory would contain the entire contents of /mnt/extSdCard.

    Step 4: using adb, or a terminal on my tablet running "su", or something like RootExplorer, change the contents of /etc/fstab (or whatever that file is called under Android), so that the former mount point for /mnt/sdcard is now called /mnt/extra, and so that the former mount point for /mnt/extSdCard is now called /mnt/sdcard. In other words, the new mount point for the swappable card will be /mnt/sdcard, and the new mount point for the internal card will be /mnt/extra.

    Step 5: clear out all of /mnt/sdcard

    Step 6: clear out all of /mnt/extSdCard

    Step 7: run the following commands as root (or whatever similar commands correspond under Android) ...

    umount /mnt/sdcard
    umount /mnt/extSdCard
    mount -av​

    The latter should perform all the mounts in /etc/fstab so that my renamed mounts will go into effect.

    Step 8: restore the backed up /mnt/sdcard contents from my desktop computer to the tablet's new /mnt/sdcard filesystem (including that new "ext" subdirectory)

    Step 9: restart my tablet

    (or perhaps exchange steps 8 and 9)

    If all this works, /mnt/sdcard should now be the large swappable card containing the original internal sdcard contents plus that "ext" subdirectory with the original contents of "extSdCard". Also, /mnt/extra should be the empty internal sdcard, which I can use for whatever I want.

    Aside from the differences between the commands I gave above (standard Unix/Linux) and the Andoid versions of those commands, do you folks think this procedure will work?

    Thanks in advance.


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