Plesk for Linux: limiting database size

I have two servers with Plesk Panel: a Linux one and a Windows one.

From the Win version i can specify the maximum MySQL database size for a given user , or user template,
but on Linux that option is not available, and i need to apply this limit (otherwise, all users will have an unlimited DB!)

I have Plesk version 9.3.0 on CentOS (Linux 2.6.28.4-xxxx-std-ipv4-32) ,
and Plesk for Windows 9.0.1

Any suggestion?

p.s. I've also tried using the API, but the Plesk for Linux gives this error:
<errcode>2308</errcode>
<errtext>Limits for the resource type mysql_dbase_space cannot be set.</errtext>
On windows all goes well with the API too


p.p.s. the mysql version on linux is mysql 5.0.45-7.el5 , and on windows is MySQL 5.0.45