Can't update to 1.8.5 - alway this error

Hi, yesterday, I tried using the WebUI to upgrade to 1.8.5 version of EdgeOS.  It failed at copying it. So I tried a reboot, and it fail at reboot! and I tried a SSH or CLI button in WebGUI, and it also failed with a message about /bin/vbash I/O error...  

so today, I hard rebooted the router.  Then, thru SSH, I did the following commands :

ubnt@ubnt:~$ add system image https://dl.ubnt.com/firmwares/edgemax/v1.8.5/ER-e100.v1.8.5.4884695.tar
Version [v1.7.0.4783374.150622.1534] is about to be replaced
Are you sure you want to replace old version? (Yes/No) [Yes]: yes
Trying to get upgrade file from https://dl.ubnt.com/firmwares/edgemax/v1.8.5/ER-e100.v1.8.5.4884695.tar
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100 82.7M  100 82.7M    0     0  3858k      0  0:00:21  0:00:21 --:--:-- 4054k
Download suceeded
Checking upgrade image...Done
Preparing to upgrade...Done
Copying upgrade image...
Message from syslogd@ubnt at Jun 14 22:46:24 ...
 kernel:journal commit I/O error
Done
Removing old image...Failed to remove old image
rm: can't remove '/root.dev/squashfs.tmp': Read-only file system
rm: can't remove '/root.dev/squashfs.tmp.md5': Read-only file system
rm: can't remove '/root.dev/version.tmp': Read-only file system
ubnt@ubnt:~$ show system image
The system currently has the following image(s) installed:

v1.8.0.4853089.160219.1607     (running image) (default boot)
v1.7.0.4783374.150622.1534

ubnt@ubnt:~$

So, it failed again.  Is this my USB key that is again corrupted ?  I already changed it once 5-6 months ago !

Or I miss space ?  How to cleanup space?  I had the DPI enabled and did couple of torrenting since a month.  I saw that the DPI pages was full of connections.  Do I need to disable that and delete the tmp files somewhere ?

Please help ! Image may be NSFW.
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