From : http://serverguru.blogspot.be/2009/09/vzquota-error-quota-on-syscall-for-id.html

Reason: The vzquota of that particular vps still running in the server. So you have to drop the quota before applying the new changes.

remove /var/vzquota/quota. and drop the particular quota

• rm /var/vzquota/quota.110
• vzquota drop 110
• vzctl start 110