@jdaviescoates said in Nextcloud says 5.3GB used, Cloudron says Nextcloud is 19.16GB, why?:

That's "just" a difference of 2.66GB (which I guess could mostly be just Nextcloud files themselves)

So, assuming that is mostly just Nextcloud files themselves (I may do a clean install at some point just to see how big that is), I think this can be marked as solved.

Ah we did hit that kernel/initramfs issue with /boot getting filled up by Ubuntu already before. If it is 100% full even the autoremove fails.

Would be good to actually not just maybe warn about that, but see how the whole situation can be mitigated in the first place. Afterall it is not much use to have that many kernel versions around.

@girish & @marcusquinn thanks for the hints!

Finally the AWS guide did the trick, it was a 2 step approach (in my case):

sudo growpart /dev/sda 3

sudo resize2fs /dev/sda3