System Disk Full - Cannot Log in to OMV

My OMV system has become full for reasons I cannot explain. It appears I cannot login because the disk is full have read all the threads. Tried removing plexmediaserver but that did nothing. I cannot find what is causing it to fill up. Any help appreciated.

I cannot login locally. Output as follows

root@stoneyserve:~# du -d1 -h
12K ./.ssh
8.0K ./.vim
76K .

Sorry. Yes I can log in via CLI. I cannot log in to the GUI Wen I enter UN and PW, it just goes back to blank login screen with no error message

Output

root@stoneyserve:~# du -d1 -h /
16K /lost+found
4.0K /opt
du: cannot access ‘/proc/15452’: No such file or directory
du: cannot access ‘/proc/15501’: No such file or directory
du: cannot access ‘/proc/15502’: No such file or directory
du: cannot access ‘/proc/15503’: No such file or directory
du: cannot access ‘/proc/15504/task/15504/fd/3’: No such file or directory
du: cannot access ‘/proc/15504/task/15504/fdinfo/3’: No such file or directory
du: cannot access ‘/proc/15504/fd/4’: No such file or directory
du: cannot access ‘/proc/15504/fdinfo/4’: No such file or directory
0 /proc
21M /boot
8.0K /tmp
8.4M /bin
4.0K /home
0 /dev
76K /root
2.3G /var
12M /run
396G /srv
7.7M /etc
78M /lib
4.0K /mnt
4.0K /export
4.0K /selinux
9.6M /sbin
0 /sys
1.2G /usr
58M /media
400G /

It is an 8GB drive (/dev/mmcblk1p) but showing up as 4GB

Output of df -h

FilesystemSizeUsed Avail Use% Mounted on
udev 10M 0 10M 0% /dev
tmpfs 399M 17M383M 5% /run
/dev/mmcblk1p1 3.7G 3.6G 0 100% /
tmpfs 997M 0997M 0% /dev/shm
tmpfs 5.0M8.0K5.0M 1% /run/lock
tmpfs 997M 0997M 0% /sys/fs/cgroup
tmpfs 997M 12K997M 1% /tmp
/dev/sda1 2.7T396G2.3T15% /srv/dev-disk-by-id-usb-CloudShell2-0EEA16EF0C17-External_Disk_3.0-part1
folder2ram997M 0997M 0% /var/tmp
folder2ram997M324K997M 1% /var/lib/openmediavault/rrd
folder2ram997M784K997M 1% /var/spool
folder2ram997M 15M983M 2% /var/lib/rrdcached
folder2ram997M8.0K997M 1% /var/lib/monit
folder2ram997M 31M967M 4% /var/lib/netatalk/CNID
folder2ram997M456K997M 1% /var/cache/samba
tmpfs 200M 0200M 0% /run/user/0

I just rebuilt a new system drive with a larger SD Card (16GB) but OMV is showing the drive as being 7GB. DId I skip a step in expanding the image? Thanks very much for any advice on this.

Thanks. Will read the readme.txt