USB Mass Storage on Android Devices

Another working title for this page could be, "I just want to connect my phone to my PC and have it show up as a drive letter so I can easily transfer files."

USB mass storage is the standard protocol used by flash drives, external hard drives, SD cards, and other USB storage devices. It also was used by Android devices and even many basic phones. At some point the brains that develop Android decided to do away with this useful feature. They have legitimate arguments against the feature. Yet, the feature is very much missed by those who used it.

The new options, Media device (MTP) or Camera (PTP) mode, are either unavailable to Windows XP and other OS users, or too limited.

USB Mass Storage Mode

This is the most basic and best possible or least complicated possible way to connect your phone to a personal computer with a USB data cable. When you connect the data cable between the phone and the computer, a drive letter appears in the operating system which allows browsing, reading, and writing to the storage memory on the phone. It is also useful for copying pictures from the phone to the computer as well as backing up data such as your contacts.

Some new so called Smart Phones require a Vista or newer version Microsoft Windows Media Player to transfer data between the phone and the computer. This is not standard. This is not USB Mass Storage Mode. USB Mass Storage on Android Devices has been discontinued as of Android version 4.1.1.

In USB Mass Storage Mode, your phone will appear to the computer just like any other flash memory type, such as a thumb-drive or SD card.

A simple and small in file size driver might be necessary to make this work. Bloatware such as Samsung Kies should _NEVER_ have to be installed for a basic USB mass storage mode connection. Typically, if you skip driver installation, Microsoft Windows XP or later will still allow USB Mass Storage mode as long as the phone supports it and USB Debugging is enabled.

Why Android Devs Ditched USB Mass Storage

USB Mass Storage made it easy to connect your phone to a PC and transfer files. It was not necessary to install any special drives on the PC. The PC would detect the phone, and you could simply cancel the driver search dialog, and then wait a few seconds for the new drive letter to appear in Explorer/My Computer. Files could be transferred both ways. However, while connected and in USB Mass Storage Mode, which had to be set on the Android, the SD Card was unmounted and unavailable to the Android itself.

When connected to the computer, the mount point was disconnected from the Android operating system running on the device. Any files or apps stored on the SD card or USB storage would be unavailable when it was connected to the computer. This caused some interesting side effects. Icons for apps that were set to run from external storage would disappear from the Android desktop. Each app icon would have to be manually placed back on the desktop by the user. That is one example of a side effect.

Developers also didn't care for the limitations imposed on the format of the external storage. The SD card had to be formatted in a file system compatible with Microsoft Windows and therefore fees had to be paid to Microsoft for the right to use the format.

see: external sd card is now read only

Why the alternatives fall short

MTP functions a lot like USB mass storage. For example, an MTP device shows up in Windows Explorer so you can browse and transfer files. Linux also include offers for MTP devices via libmtp. So, Android devs want us to use MTP as an alternative to USB Mass Storage. They say MTP is better because access to the external storage can be shared.

• Windows XP doesn't include native drivers for MTP.
• Apple Macintosh offers absolutely no support for MTP.

A Media Transfer Protocol (MTP) driver for XP is (was) available from Microsoft. However, Microsoft discontinued support for Windows XP in 2009. The MTP driver they offer is only partially functional and does not work with all Android devices.

Choosing the Camera (PTP) option is no substitute. This only allows you access to the DCIM (Camera image) folder on the Android, and files can only be "read." You cannot copy files from the PC to the Android in PTP mode.

Owners of the Samsung Galaxy Tab 2 (7.0) and a Windows XP computer have no resolution to these limitations. This particular tablet will not support USB Mass Storage mode, Samsung offers no driver, and MTP doesn't work with this device even when the Media Transfer Protocol (MTP) driver for XP is installed on the PC.