Samsung Galaxy S3 and Galaxy Note 2 users can enable Mass Storage Mode or UMS Mode or whatever you call it, by installing a simple APK file on their devices. But in order to make it work, it is required that your device is rooted.
In the newer version of TouchWiz, Samsung has disabled mounting of the media storage. That’s why when we connect the device to our computer, a GT-I9300 folder comes up. The connectivity mode is called as MTP (Media Transfer Protocol) We get many errors while copying and transfers are horribly slow in this kind of connectivity, plus there are limitations too while transferring files of other extensions.
SGS3Easy UMS is an application created created by XDA developers forum member Kopfgeldjaeger, this tiny application enables users to connect their devices to the computer in UMS Mode.
SGS3EasyUMS executes the following command:
setprop persist.sys.usb.config mtp,adb
echo /dev/block/vold/179:17 > /sys/devices/platform/s3c-usbgadget/gadget/lun0/file
The app was specifically created for the Samsung Galaxy S3, but when tried on Note 2 it worked too. I think this should work for Note 10.1, S3 Mini and other Samsung devices which come with MTP enabled. You can try it on your device and tell us about the results.
That is how you can enable mass storage mode on your Samsung Galaxy S3 or any other device.