Jolla: Android on SD-Card


The Jolla has 16 GB internal disk space which is filled by Android apps like OsmAnd and Spotify pretty fast.
Thus I've developed a way to move the data of these apps to sd-card.


All of the following commands have to be run as root.
Thus you have to be careful otherwise you'll break your phone.


There is no warranty that this setup works for any system which provide the dependencies listed below.
I'm just providing these information because it worked for me.
If you have questions you can leave a message here but I decide whether I'll answer and help or not.

If you follow these instructions you'll move all data saved by Android apps running on the SailfishOS of a Jolla to the sd-card of your phone.

That way you might use up to 64 GB of disk space for maps, media files and everything else stored by Android apps.


  • a Jolla phone ;D
  • SailfishOS >= (earlies versions might work but aren't tested)
  • Dev-Mode enabled
  • password to become root
  • SD-Card with enough space
  • some Linux knowledge


The following instructions use the following settings:

  • sd-card contains 1 partition
  • the partition device is mmcblk1p1

If your setting differs from these you have to change the corresponding commands.

  1. insert the sd-card into your phone
  2. start terminal
  3. change to root user
  4. check whether card was found
    ls /dev/mmcblk1
    • the card was found if the output is
    • if an error is thrown the card wasn't found → you have to reboot your phone
  5. check whether the card is mounted
    mount | grep mmcblk1
    • the card is mounted if the output is like
      /dev/mmcblk1p1 on /media/sdcard/<UUID_of_partition> type btrfs (rw,nosuid,nodev,noexec,noatime,dirsync,thread_pool=4,ssd,noacl,space_cache)
    • the card isn't mounted if the output is empty
  6. if the card is mounted unmount all partitions of it
    umount /dev/mmcblk1p1
  7. format the partition you want to use for Android data :!: all data will be lost :!:
    mkfs.btrfs /dev/mmcblk1p1
  8. mount sd-card add mmcblk1p1
    • the partition will be mounted on /media/sdcard/<UUID_of_partition>
  9. stop all Android apps
  10. stop Android layer
    systemctl stop aliendalvik
  11. copy existing data of apps
    rsync -a --progress /data/media/ /media/sdcard/"$(blkid -o value -s UUID /dev/mmcblk1p1)"/android_storage/
  12. correct the permissions
    chown -R media_rw: /media/sdcard/"$(blkid -o value -s UUID /dev/mmcblk1p1)"/android_storage/
    chmod -R 770 /media/sdcard/"$(blkid -o value -s UUID /dev/mmcblk1p1)"/android_storage/
  13. create systemd-service file
    echo "[Unit]
    Description=Mount sd for android
    ExecStart=/usr/local/sbin/ start
    ExecStop=/usr/local/sbin/ stop
    [Install] display.service" > /etc/systemd/system/mount-sd4android.service
  14. create helper script
    echo '#!/bin/bash
    sd_uuid="$(blkid -o value -s UUID /dev/mmcblk1p1)"
    if [ "$1" == "start" ]
    	systemctl stop aliendalvik
    	mount -o bind /media/sdcard/"${sd_uuid}"/android_storage /data/media
    	systemctl start aliendalvik
    elif [ "$1" == "stop" ]
    	systemctl stop aliendalvik
    	umount /data/media
    fi' > /usr/local/sbin/
  15. change permission of helper script
    chmod ug+x /usr/local/sbin/
  16. enable systemd-service
    systemctl enable mount-sd4android.service
  17. reboot your phone
  18. start terminal
  19. check if all went well
    df -hT
    • all is ok if the output looks like:
                   btrfs     30G  8.4G   21G  29% /media/sdcard/4f1f8dbc-ed55-4b6c-8290-ac97e15b221f /dev/mmcblk1p1
                   btrfs     30G  8.4G   21G  29% /data/media
      /dev/fuse     fuse     30G  8.4G   21G  29% /home/nemo/android_storage
  20. if all went well delete the old data
    devel-su stop
    rm -rf /data/media/* start


Thanks for the great howto!

In step 7 I had to do a mkfs.btrfs -O ^extref -f /dev/mmcblk1p1

to switch off the 'extref' extension. With 'extref' the card wouldn't mount on my jolla.

1 |
Lew Palm
| 2015/04/11 11:32 | reply

In step 6 I had to unmount from the Settings > Storage > memory card (press, hold and unmount)

error message was: # umount: /media/sdcard/6530-6331: target is busy

thanks for the brilliant tutorial

2 |
Josef Noll
| 2017/07/21 05:35 | reply

@Josef Noll: one more step: I had to add the following line after „systemctl start aliendalvik“ mount –bind /media/sdcard/„${sd_uuid}“/android_storage /home/nemo/android_storage

Reason was that aliendalvik mounted the internal jolla sd card again. Checked with df -hT

3 |
Josef Noll
| 2017/07/21 07:55 | reply

N A᠎ E E E
linux/jolla_android_on_sd-card.txt · Zuletzt geändert: 2014/06/21 12:50 von Andrwe Lord Weber