I just got an email from someone who had watched one of my old ISA Server 2006 webcasts. She had a couple of interesting questions, and I thought I'd share the answers to her email with you.
Q. How do you clear the cache in ISA Server 2006?
A. To clear the cache, disable the cache through ISA Server Management, and then delete the cache storage file, such as Dir1.cdat (the default name of the ISA Server cache file). There is a cache file in the Urlcache folder on each drive that is configured for caching. After you delete the cache file, enable the cache in ISA Server Management. There is also a sample script that describes how to clear the cache programmatically. For information, see "Deleting Cache Contents" at the Microsoft TechNet Web site. In ISA Server 2006 Enterprise Edition, this tool must be run on each array member.
Q. How does ISA Server 2006 remove cached data?
A. If the cache content file is too full to hold a new object, ISA Server removes older objects from the cache, by using a formula that evaluates age, how often the object is accessed, and size.
Q. Is there any way to see what is in the ISA Server 2006 cache?
A. Try this to view the URLs in the cache in real-time: http://www.microsoft.com/downloads/details.aspx?familyid=b9ecfcd3-c13f-4447-83ed-add9a8ea45db&displaylang=en