[Android General] philippe734:
Hi all,

Here another method to format to ext4 your internal sdcard (usb storage) of any Android device. This trick work also with external sdcard. Since Galaxy S3, many devices have already the internal sdcard in ext4, so check your sdcard file system type with Diskinfo from Play Store. This guide is great for Galaxy S1 or S2 for exemple.

Required :

- Your computer

- Android with recovery (cwm, Philz...)

- Live CD of Parted Magic 2013 : link

- USB cable

- Android 4.x

In brief :

- Copy all data of your internal sdcard to your computer.

- Format to ext4 your internal sdcard with Parted Magic AND NOT WINDOWS.

- Restore your data to your internal sdcard.

- Fix permissions* (very important).

- Check.

"Thanks chrhei, laotzy"

Why ext4 ?

- Ext4 is native file system for Android, while exfat is not.

- The system internal partitions (/efs /data /system /cache /preload) use ext4, natively.

- The famous music bug on Android 4.4 AOSP will be gone.

- CM has poor exfat support, while fat32 is not recommended for big files (over 2 GB) because it doesn't work well with them.

- Ext4 has better stability and performance, especially on Android devices, compared to exfat and fat.

"Thanks JustARchi"

Steps by steps :

- Download iso of Parted Magic 2013 freeware (Mac, Linux, Windows) : here.

- Burn the live cd on a real CD or make a live usb stick.

- On your computer, reboot on Parted Magic (live cd or usb stick) :

- On your Android device, reboot in recovery :

- Plug Android to computer with usb cable.

- In recovery, first select mount and storage. Then, select mount USB storage. Then, don't touch recovery upto the end of process. If you go back, then recovery unmount sdcard and break the process :

- On computer, with Parted Magic, open file manager and check if you can browse files of your internal sdcard :

- If browsing ok, then copy all data of internal sdcard to computer.

- Please note carefully the name of your internal storage in parted magic, like sde1 or sdb2…

- On computer, open Partition editor (Gparted).

- On partition editor, select your internal sdcard from its name.

- Be carefull to select your internal sdcard and not your hard drive of your computer !

- On partition editor, format your internal sdcard to ext4 from a right click on its partition. :

- Wait the end of process :

- When the format is over, reboot the recovery NOT Android, do it from the advanced options.

- In recovery, go to storage and select USB mount storage.

- On computer with Parted Magic, open file manager and go to your internal sdcard now ext4.

- Restore all data saved to your internal sdcard.

- Reboot android.

- With a terminal in Android, execute the command: su

- Before you start fixing permissions don't forget to type su in your phone's Terminal

- Then, check permissions and type :

ls -la /mnt/media_rw/

The return will be like :

drwxrwxr-x media_rw media_rw 2014-08-20 21:56 sdcard0

drwxrwxr-x media_rw media_rw 2014-08-21 18:32 sdcard1

- To fix permissions, you have to copy everything below, line by line, into the Terminal. Use Android with a web browser as firefox to navigate upto here and copy past to the terminal this lines :

cd /mnt/media_rw/

find sdcard0 -type d -exec chmod 0775 {} \;

find sdcard0 -type d -exec chown media_rw:media_rw {} \;

find sdcard0 -type f -exec chmod 0775 {} \;

find sdcard0 -type f -exec chown media_rw:media_rw {} \;

- Check permissions to see the differences :

ls -la /mnt/media_rw/

- If it is an external sdcard, do the same but replace sdcard0 by sdcard1

- Reboot Android normally (not into terminal).

- Voilà !

- Now, you need to check 2 things : the permissions and the ext4 file system of the sdcard formated :

Please, verify this :

Check permissions : To check if permissions is done, go to browsing files under Android, with an app to browsing files as es file explorer. Then, create a directory at the root of your sdcard ext4 (as /storage/sdcard0/), then delete it. If you will able to delete the folder, then permissions is fine. If not, then go back to follow again steps about fix permissions.

Check your ext4 sdcard: Use Diskinfo from Play Store to check the file system of your sdcard before and after formated : here. There will several partitions, please select the sdcard formated and check its file system.

Video of this guide, but please, read the guide before :

Part 1, backup and format under Parted Magic : here

Part 2, fix permissions with a terminal under Android : here

Why ext4 and another methods here : http://bit.ly/1oYzi3A

Windows users : After formated to ext4, to access to your internal sdcard, you must connect your device in USB in MTP and not USB mass storage (UMS). Because with UMS, no way to access to your internal sdcard from windows. You can set MTP in the parameters of Android :

Anyway, with UMS, to read the new ext4 volumes in Windows, use ext2Fsd.

* Fix Permissions : after formated the sdcard to ext4, there is a very annoying issue. No way to create or delete directory or file at root of this storage. So, there will be big troubles, like unable to backup, no way to install new apps which have to write on this storage, unable to update CM... Without fix permissions, the sdcard will be a kind of read protected storage at root directory.

Before formated, the internal sdcard on my Galaxy S2 was vfat. Here my Galaxy S2 running CM11, after format's process, the internal sdcard is now ext4 :