What is the mailbox database cache?
The database cache stores a subset of the mailbox database in the main memory of the mailbox server. This has the advantage that frequently used data does not have to be read again and again from the relatively slow hard disks of the servers, but instead comes from the fast main memory. Furthermore, this reduces the I/O processes on the hard disks.
Memory requirements for the database cache
ESE requires a guaranteed minimum amount of RAM on the mailbox servers for the database cache. How much RAM is required depends on the number of databases
| Number of mailbox databases | Memory per mailbox database for the database cache |
| 1-10 | 2 GB |
| 11-20 | 4 GB |
| 21-30 | 6 GB |
| 31-40 | 8 GB |
| 41-50 | 10 GB |
How large is the database cache on a mailbox server?
| RAM of the server | Cache size mailbox server | Cache size Multi Role Server |
| 2 GB | 512 MB | - |
| 4 GB | 1 GB | - |
| 8 GB | 3.6 GB | 2 GB |
| 16 GB | 10.4 GB | 8 GB |
| 24 GB | 17.6 GB | 14 GB |
| 32 GB | 24.4 GB | 20 GB |
| 48 GB | 39.6 GB | 32 GB |
| 64 GB | 53.6 GB | 44 GB |
| 96 GB | 82.4 GB | 68 GB |
| 128 GB | 111.2 GB | 92 GB |
How can I change the size of the database cache?
Adjusting the size of the cache can be useful if other services besides Exchange are running on the server (fax solution, etc.)The size of the database cache can be changed using ADSIedit.
Zunächst wird eine Verbindung zum Namenskontext „Konfiguration“ aufgebaut
Then navigate to the following entry
Ein Rechtsklick auf „CN=InformationsStore“ öffnet das Kontextmenü, darin „Eigenschafte“ wählen. Jetzt die Werte für „msExchESEParamCacheSizeMax“ und „msExchESEParamCacheSizeMin“ suchen
The values for the maximum and minimum database cache can now be specified here. The values must be specified here in 32 KB pages and not simply as MB or GB.
Example:
The cache should be at least 2 GB in size: 2 GB = 2048000 KB / 32 KB = 64000
Bei „msExchESEParamCacheSizeMin“ muss also 64000 eingetragen werden.
The cache should have a maximum size of 4 GB: 4 GB = 4096000 KB / 32 KB = 128000
Bei „msExchESEParamCacheSizeMax“ muss also 128000 eingetragen werden.
Zum Schluss muss noch der Dienst „Microsoft Exchange Informationsspeicher“ neugestartet werden.