Check what process are blocking the partition /storage to be unmounted
lsof | grep "/storage" (will return the PID of the process)
Check if these processes are in the systemd tree and are controlled by systemd.
systemctl status will show the systemd tree.
In may case I had to stop the following:
systemctl stop cron.service
systemctl stop connman.service
systemctl stop kodi.service
fuser -m /storage if there are still process blocking that directory.
In case some PID are returned you can check what process is associated with that PID running
ps -ef | grep $PID.
If you see something like
-sh it is your ssh session that is in the /storage directory.
cd / to go in the root.
Otherwise you can kill that process with
kill -9 $PID.
Now you can safely unmount the /storage directory via
Now you can resize the partition (I will report again since some commands are changed)
Ensure which particion /storage belong to
In most of the case will be
/dev/mmcblk0p2 (which is partition 2)
Open parted for the device /dev/mmcblk0
Show partitions (we alredy now which partition we want to resize)
Resize the partition (this case partition 2 till the end)
resize 2 -1
Resize the file system
e2fsck -f /dev/mmcblk0p2
mount /dev/mmcblk0p2 /storage
If you want to resize /flash is a completely different story.