USB mount : space issue

Question

I added a 256 GB USB stick , mounted in :

/mnt/mydisk

I setup all my docker to have they files stored in the USB stick:

e.g:

docker create --name=transmission \
-v /mnt/mydisk/Download/Deluge/ConfigTransmission:/config \
-v /mnt/mydisk/Download/Deluge/:/downloads \
-v /mnt/mydisk/Download/Deluge/Data:/watch \
-e PGID=1000 -e PUID=1000 \
-e TZ=Europe/Dublin \
-p 9091:9091 -p 51413:51413 \
-p 51413:51413/udp \
lsioarmhf/transmission

although it's seems I don't have enough space downloading a light linux iso...

Not sure what's happening

NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda           8:0    1 234.4G  0 disk 
├─sda1        8:1    1  31.5K  0 part 
├─sda2        8:2    1 234.4G  0 part 
└─sda3        8:3    1     8K  0 part 
mmcblk0     179:0    0  59.5G  0 disk 
├─mmcblk0p1 179:1    0   256M  0 part /boot
└─mmcblk0p2 179:2    0  59.2G  0 part /

UPDATE:

I think I used this for the mount :

sudo apt install exfat-fuse 
sudo mount /dev/sda2 /mnt/mydisk

and I add the device to /etc/fstab (something like UUID=THEUUID /mnt/mydisk xfat defaults,auto,users,rw,nofail 0 0)

although, it's seems the fstab file changed, as nothin is listed any more

sudo nano /etc/fstab
Binary file /etc/fstab matches
# a swapfile is not a swap partition, no line here
#   use  dphys-swapfile swap[on|off]  for that

When I try to manually mount :

pi@raspberrypi:~ $ sudo mount /dev/sda2 /mnt/mydisk
FUSE exfat 1.3.0
WARN: volume was not unmounted cleanly.
fuse: mountpoint is not empty
fuse: if you are sure this is safe, use the 'nonempty' mount option

Answer 1

You probably have a corrupted /etc/fstab file, so the mount failed and the data was written on the SD card. To correct the problem execute the following steps.

Replace the content of /etc/fstab with the following, using the UUIDs you get from blkid

proc            /proc           proc    defaults          0       0
PARTUUID=6c586e13-01  /boot           vfat    defaults          0       2
PARTUUID=6c586e13-02  /               ext4    defaults,noatime  0       1

Temporarily mount the USB stick on a different directory e.g. /mnt/tempUSB

sudo mkdir /mnt/tempUSB
sudo mount /dev/sda2 /mnt/tempUSB

and move the content from /mnt/mydisk to the USB stick

mv /mnt/mydisk/* /mnt/tempUSB

unmount the stick, disconnect it, and delete the temporary directory

sudo umount /mnt/tempUSB
sudo rm /mnt/tempUSB

Add the new line to /etc/fstab

UUID=THEUUID /mnt/mydisk xfat defaults,auto,users,rw,nofail 0 0

save /etc/fstab and check the update was successful

cat /etc/fstab

the output should have 4 lines, with the filesystems /proc, /boot, /, and /mnt/mydisk. Connect the USB stick and mount it using the content of /etc/fstab sudo mount -a Now you should be able to write on it.

To check if the setup is correct you can write a new file in /mnt/mydisk, unmount the stick, connect to another PC and check if the new file is there.