SharePoint 2007 - Update multiple Site Collections quota values

Out of the box SharePoint 2007 does not offer an automated way to modify existing site collections with a quota value. For example if you have a quota "Extranet" with a size limit of 3GB that's been applied to 1000 sites currently there is no method to update this value on batch


However using the "SharePoint Administration Toolkit" you can run the following command


The following would update all the sites using the quota extranet with the new value

• stsadm –o updatequota –quotaname Extranet

The following would update all the sites using the quota extranet with the new value but only that are contained in WSS_Content_001 

• stsadm –o updatequota –quotaname Extranet -contentdb WSS_Content_001

For more examples follow this link 
http://technet.microsoft.com/en-us/library/ee449569(office.12).aspx