Seems like it might be an OpenVZ VPS. Have a look at /etc/mtab. You should see something like this:
Code:
/dev/simfs / reiserfs rw,usrquota,grpquota 0 0
If you don't see "usrquota,grpquota" then you won't be able to use quotas, and on OpenVZ you can't edit that disk configuration yourself. It has to be done on the host node by your hosting company.