http://blogs.technet.com/kevinholman/archive/2008/11/04/boosting-opsmgr-performance-by-reducing-the-opsdb-data-retention.aspxHere is a little tip I often advise my customers on..... The default data retention in OpsMgr is 7 days for most data types:     These are default settings which work well for a large cross section of different agent counts.  In MOM 2005en-USCommunityServer 2.1 SP1 (Build: 61025.2)