Total Aggregate Cache Size

The sum of all caches used simultaneously must remain smaller than the total size of available physical memory, minus the memory intended for file system cache, minus the memory intended for other processes such as Directory Server itself.

For 32-bit servers, the total aggregate cache size must be limited so that the total Directory Server ns-slapd process size is less than the maximum process size allowed by the operating system. In practice, this limit is generally in the 2-3 GB range.

If suffixes are initialized while Directory Server is online, the sum of the database cache, the entry cache, and the import cache sizes should remain smaller than the total size of available physical memory.

If all suffixes are initialized while Directory Server is offline, the import cache does not coexist with the database cache, so the same memory can be allocated to the import cache for offline suffix initialization and to the database cache for online use. If you opt to implement this special case, however, ensure that no online bulk loads are performed on a production server. The sum of the caches used simultaneously must remain smaller than the total size of available physical memory.

For very large caches, it is important that the memory used by Directory Server does not exceed the size of available physical memory. If the available physical memory is exceeded, the system pages repeatedly and performance is degraded.