How to modify the Store Database maximum cache size in Exchange 2000 Server (266768)

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Warning If you use the ADSI Edit snap-in, the LDP utility, or any other LDAP version 3 client, and you incorrectly modify the attributes of Active Directory objects, you can cause serious problems. These problems may require you to reinstall Microsoft Windows 2000 Server, Microsoft Windows Server 2003, Microsoft Exchange 2000 Server, Microsoft Exchange Server 2003, or both Windows and Exchange. Microsoft cannot guarantee that problems that occur if you incorrectly modify Active Directory object attributes can be solved. Modify these attributes at your own risk.
Exchange 2000 is shipped with a hard set maximum Store Database cache size. This default value is 900 megabytes (MB). On computers that have over 2 gigabytes (GB) of memory, you may want to increase the size of this cache. Because of virtual address space limitations, you should not set this value higher than 1216 MB.

Note The 900 MB limit ensures that the store process always has sufficient virtual address space (memory) to allocate from. If you increase this value too much, your computer can become unstable.

For more information, click the following article number to view the article in the Microsoft Knowledge Base:
The following factors affect the virtual address space size in the Store.exe process:

• Initial allocation on startup.
• The number of storage groups or MDB Messaging databases on the server.
• The number of threads that are running.
• The size of the Store Database cache.

Before you increase the maximum cache size, Microsoft recommends that you use the System Monitor tool to monitor the memory of the server under normal load. Check the Process-Virtual Bytes System Monitor object that is mapped to the Store.exe instance to determine an accurate value for the virtual address space that the store has allocated. On a server that has a /3 GB switch in the Boot.ini file, the virtual address space should be below 2.8 GB. On a server that does not have the /3 GB switch in the Boot.ini file, the virtual address space should be below 1.8 GB. If you see values that are higher than these values for either configuration, do not increase the size of your maximum cache. If you see values that are lower than these values for either configuration, you can increase the size of your database maximum cache size safely. For example, if you have a /3GB-configured server, and when you use System Monitor, if the store virtual bytes setting is displayed as 2.5GB under heavy load, you can increase your maximum cache size by 300 MB, or 1216 MB in total.

Important Be aware that if you increase in the buffer size, you may adversely affect server performance. A larger buffer size means more virtual address space consumption. Because of this, if your server is already address-space constrained, and you increase the buffer size, you may create system instability. On very large mailbox servers, you may have to decrease the default buffer size to prevent system instability.

To modify msExchESEParamCacheSizeMax:

1. Start ADSI Edit.
   
   This tool is included in the Microsoft Windows 2000 Resource Kit and is also installed with the Windows 2000 support tools. To install the Windows 2000 support tools, run the setup.exe program located in the Support\Tools folder on the Windows 2000 Server CD-ROM.
2. On the Action menu, click Connect to.
3. In the Connection Point section, click Naming Context, and then click Configuration Container.
4. In the Computer section, click Select or type domain or server, and then type your domain controller.
5. Click Advanced, click Specify Credentials and then type your user name and password.
6. Type 389 in the Port Number box, and then click LDAP in the Protocol box.
7. Click OK, and then click OK again.
   
   You are then connected to the Configuration container of your domain controller.
8. Open the following object:

   Services/Microsoft Exchange/Your organization/Administrative Groups/Your administrative group/Servers/Server name/Information Store

9. Right-click Information Store, and then click Properties.
10. On the Select a property to view menu, click msExchESEParamCacheSizeMax.
11. In the Edit Attribute box, type the number of 4 kilobyte (KB) pages that you want to set the maximum cache size to.
    
    For example, 1 GB (1,024,000 KB) of cache translates to a value of 256,000. Divide the cache size that you want to set, in this example 1,024,000 KB, by 4 KB to determine the value to enter. Enter this value as a string without any commas or periods, for example, 256000.
    
    Note The msExchESEParamCacheSizeMax parameter controls the ESE buffer size. Its value is expressed as a page count, and must be set to an exact multiple of 8192 for maximum efficiency. If this value is not met, the cache size is rounded up to the next 32-MB boundary when virtual memory is allocated. If this value is incorrectly set, memory may be wasted.
    • The recommended size on servers with the /3GB switch set: 229376 (896 MB)
    • The recommended size on servers without the /3GB switch set: 147456 (576 MB)
    • The recommended maximum value: 311296 (1.2 GB)
    • The recommended value on large address-space constrained servers: 196608 (768 MB)
12. Quit ADSI Edit, and then restart the Microsoft Exchange Information Store service.

Note In a multiple domain controller site, this attribute has to replicate to the Configuration domain controller of the specific Exchange 2000 computer for the store to register the change.