Re-mount Xoom External SD Card for Read-Write

If you’re having trouble writing to your external uSD card in your Motorol Xoom, you’re not alone.

If you’re rooted the device, the solution is fairly straight forward…

Open up a terminal prompt, then type the following three commands:


umount /mnt/external1

mount -t vfat -o fmask=0000,dmask=0000,rw /dev/block/platform/sdhci-tegra.2/mmcblk1p1 /mnt/external1

When you type “su” you’ll have to approve privilege elevation.

The umount commend unmounts the uSD card

And the mount command re-mounts the uSD card with read-write privilege.

You’ll need to do this each time your Xoom is booted; and I’m going to see about creating an application that will do this auto-magically.

Once again, this will only work on a rooted Xoom; and this solution is based on reading on

I want to give credit where credit was due, but there’s a typo there (mmcblk0p1 rather than mmcblk1p1 — at least that was the device/partition on my Xoom that the uSD card appeared as).

You can determine the correct device on your Xoom by just typing “mount” in the terminal window and locating the device mounted at /mnt/external1.

Originally posted 2011-11-19 02:00:12.