kobo system partition full

Having great fun with KSM and syncthing, which was working fine, but now having some issues.

My system partition is full. It happened before but I deleted /adds/syncthing/syncthing.old after the update of syncthing. This freed up 10Mb, but it's now full again. See below.

Is there any possibility of moving stuff to the internal storage. Looking around it all looks like essential libs and apps etc. Perhaps it's possible to resize the system partition?

Any suggestions welcome, thanks!

df -h
Filesystem Size Used Available Use% Mounted on
/dev/root 247.9M 247.0M 979.0K 100% /
none 16.0M 0 16.0M 0% /tmp
none 248.4M 8.0K 248.4M 0% /dev
none 16.0K 4.0K 12.0K 25% /var/lib
none 16.0K 8.0K 8.0K 50% /var/log
none 128.0K 8.0K 120.0K 6% /var/run
/dev/mmcblk0p3 3.2G 1.9G 1.3G 60% /mnt/onboard
/dev/mmcblk1p1 59.5G 41.9G 17.6G 70% /mnt/sd


du -sh /*

3.0K /Settings
2.0K /Sync
28.0M /adds
6.5M /bin
8.0K /dev
787.0K /drivers
4.0M /etc
112.0K /fs.md5sum
0 /isforksm.txt
8.3M /lib
1023.0K /libexec
0 /linuxrc
12.0K /lost+found
43.8G /mnt
0 /proc
3.0K /qtembedded-0
154.0K /root
421.0K /sbin
0 /sys
0 /tmp
118.2M /usr
24.0K /var