Registry Hive Fragmentation Leads to Excessive Size

SYMPTOMS

Processes that use the registry to repeatedly modify the same values in small increments can cause excessive memory fragmentation in the corresponding registry hive. The sum of the fragmented cells can become so large that the hive size winds up many times larger than the sum of actual data in the hive. Eventually, the sum of the hive will exceed the Registry Size Limit (RSL), causing subsequent modifications to fail until the RSL is increased. As an example consider the SAM hive used to store Windows NT accounts. The SAM size frequently exceeds projected sizes due to the fact that it fragments the SAM hive when adding members to large groups.