How to create a raid on Owncloud already working?

root@DietPi:~# cat /etc/fstab
# You can use "dietpi-drive_manager" to setup mounts.
# NB: It overwrites and re-creates physical drive mount entries on use.
#----------------------------------------------------------------
# NETWORK
#----------------------------------------------------------------
192.168.1.112:/ /mnt/nfs_client nfs nofail,noauto,x-systemd.automount

#----------------------------------------------------------------
# TMPFS
#----------------------------------------------------------------
tmpfs /tmp tmpfs size=1024M,noatime,lazytime,nodev,nosuid,mode=1777
tmpfs /var/log tmpfs size=50M,noatime,lazytime,nodev,nosuid,mode=1777

#----------------------------------------------------------------
# MISC: ecryptfs, vboxsf, glusterfs, bind, Btrfs subvolume mounts
#----------------------------------------------------------------


#----------------------------------------------------------------
# SWAP SPACE
#----------------------------------------------------------------
/var/swap none swap sw

#----------------------------------------------------------------
# PHYSICAL DRIVES
#----------------------------------------------------------------
PARTUUID=0e2887fb-02 / ext4 noatime,lazytime,rw 0 1
PARTUUID=0e2887fb-01 /boot vfat noatime,lazytime,rw 0 2
UUID=2966eeaa-38a0-4cef-9469-fcd591d85249 /mnt/backup ext4 noatime,lazytime,rw,nofail,noauto,x-systemd.automount
UUID=30c34f48-55f3-4e6e-b18f-2a72424cff6e /mnt/raid0 ext4 noatime,lazytime,rw,nofail,noauto,x-systemd.automount
root@DietPi:~# ls -la /mnt/raid0/ls -la /mnt/raid0/

ls: cannot access '/mnt/raid0/ls': No such file or directory
/mnt/raid0/:
total 28
drwxr-xr-x 4 root     root      4096 Feb 23 22:16 .
drwxr-xr-x 9 root     root      4096 Feb 23 22:04 ..
drwx------ 2 root     root     16384 Feb 23 22:06 lost+found
drwxr-xr-x 2 www-data www-data  4096 Feb 23 22:16 owncloud
root@DietPi:~# 
root@DietPi:~# ls -la /mnt/raid0/
total 28
drwxr-xr-x 4 root     root      4096 Feb 23 22:16 .
drwxr-xr-x 9 root     root      4096 Feb 23 22:04 ..
drwx------ 2 root     root     16384 Feb 23 22:06 lost+found
drwxr-xr-x 2 www-data www-data  4096 Feb 23 22:16 owncloud
root@DietPi:~#