The caching daemon maintains a cache of users and groups that could not be found when searching the directory. This cache is referred to as the negative cache. Once an item is in the negative cache, no further attempts will be made to find the user/group in the directory until the negative cache entry has expired.
The default negative cache lifetime is 900 seconds, but it can be increased to suit environmental needs.
The vas.conf entry for the timeout value is:
negative-cache-lifetime = 900
The value is an integer in seconds.
If entries need to be removed from the negative cache before their lifetime has expired, the contents of this cache can be cleared by running the following:
# vastool flush negcache