I'm not sure why but I have no space available on the SDCard, I'm using a light version of Rasbian without any UI, and I have two file downloading on transmission (docker) which is suppose to be on the USB key (64GB + 6GB)

 Filesystem      Size  Used Avail Use% Mounted on
    /dev/root        59G   56G     0 100% /
    devtmpfs        1.8G     0  1.8G   0% /dev
    tmpfs           2.0G     0  2.0G   0% /dev/shm
    tmpfs           2.0G  9.8M  1.9G   1% /run
    tmpfs           5.0M  4.0K  5.0M   1% /run/lock
    tmpfs           2.0G     0  2.0G   0% /sys/fs/cgroup
    /dev/sda2       235G  120G  115G  51% /mnt/mydisk
    /dev/mmcblk0p1  253M   53M  200M  21% /boot
    tmpfs           391M     0  391M   0% /run/user/1000

how come the root directory seems to use all the space and how can I fix it

1 Answer 1


The first line of df isn't saying the root directory is using all that space, that's the root mount point, containing every directory which isn't covered by one of the other mount points.

I suspect the transmission directory isn't on the USB stick as you intend but actually on the SD card.

You can use the du command to examine where space is being used. (run these commands as root - e.g. via sudo -s). (the first two commands won't produce any output to the console).

du -xak / >/mnt/mydisk/sizes
sort -rn /mnt/mydisk/sizes >/mnt/mydisk/sorted
less /mnt/mydisk/sorted

The top entries will show where most space is going, and the numbers will be in KiB.

  • You probably right, I try this but keep getting permission issue du: cannot read directory '/lost+found': Permission denied, when I use sudo, it's take a few second but it's return nothing, same with sudo su -, du -shc /mnt/mydisk return 180G /mnt/mydisk
    – Kevin
    Commented Nov 26, 2019 at 18:35
  • PS I plugged the USB key on a desktop, I can see the dockers config and download folder / content
    – Kevin
    Commented Nov 26, 2019 at 18:55
  • 2
    You need to run these commands as root. Commented Nov 26, 2019 at 19:09
  • 2
    @Kevin The first and second commands won't produce any output to the console. The last command allows you to see the output. Commented Nov 26, 2019 at 19:11
  • FYI /lost+found is where tools like fsck will leave chunks of unidentifiable file data after fixing a corrupted root filesystem. Ideally it is always empty ;)
    – goldilocks
    Commented Nov 26, 2019 at 20:53

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.