I found the answer.
Long story short:
stop a lot of services
than remove quota info, than rebuild ..
http://www.aroundmyroom.com/2009/11/10/message-to-self-error-removing-site-in-bluequartz/
Dennis
Gerald Waugh schreef:
> On Tue, 2009-11-10 at 19:38 +0100, Dennis Slagers wrote:
>> Trying to delete a site, but
>>
>>
> <snip>
>> handlers/base/disk/clear_quota.pl failed
>> Nov 10 19:40:45 wb cced(smd)[25930]: client 5:[0:25926]: DESTROY failed
>
>> could not find any hint why clear_quota is failing.
>> Anyone?
>>
> try stop/start dbrecover and restart cced.init
> Also it may be that one of the users has files someplace other than the site folder
>
> Gerald
>