root@vps:~# cat /etc/fstab
proc  /proc       proc    defaults    0    0
none  /dev/pts    devpts  rw,usrquota          0    0
root@vps:~# touch /aquota.user /aquota.group
root@vps:~# chmod 600 /aquota.*
root@vps:~# mount -o remount /
mount: permission denied
root@vps:~# quotacheck -avugm
quotacheck: Cannot find filesystem to check or filesystem not mounted with quota option.