Can't login after update on 604T (solution)

[dec0de]

After a few of the latest updates on my 604TNAS one can suddenly neither login, nor can any computer connect to its resources.
The reason for this seems to be the update process not cleaning the /.cache directory ending up making /volume0 getting full.
This will in turn not allow you to create whatever file needed to do any web login etc.
However, luckily you can still login by using good old ssh, so all is not lost and you can fix it by doing the following:

; login to your nas
ssh admin@your_asustor_ip
; you need to be root to delete those files (the root password is probably the same as your admin password)
sudo su -
; if going for a safer option 1 do this:
mkdir /volume1/some_dir
; move these files to the big NAS for fun and profit
rzync -av --remove-source-files /.cache/* /volume1/some_dir
; and remove empty directories
find /.cache -type d -empty -delete

; if you trust yourself and want to be a bit more adventurous and going for option 2 simply do this:
rm -ri /.cache

After this you will directly be able to login to your NAS again, as well as connect to its resources.
An even better solution would be if the ASUSTOR development team would fix their scripts and
do a cleanup once the NAS is updated, until then this is the way forward...