On a standard SuSE 8.2 installation the quota module is not loaded into the kernel which is why

quotaon -avug

gives back an error.

Load the quota module manually with

insmod quota_v1

and

insmod quota_v2

To have those modules loaded on every bootup of the system please insert

modprobe quota_v1

and

modprobe quota_v2

in /etc/init.d/boot.local.