Mailbox store exceeds 12 GB

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at https://go.microsoft.com/fwlink/?linkid=34707.]  

Topic Last Modified: 2006-02-28

The Microsoft® Exchange Server Analyzer Tool queries the CIM_DataFile Microsoft Windows® Management Instrumentation (WMI) class to determine the value of the FileSize key for each Exchange mailbox store database file (.edb file) and streaming file (.stm file). The Exchange Server Analyzer also reads the following registry branch to determine the version of Exchange Server that is installed:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall\<Exchange Product GUID>

If the Exchange Server Analyzer finds that the combined size of a pair of mailbox store database and streaming files exceeds 12 GB on a computer that is running Microsoft Exchange Server 2003 Standard Edition or Microsoft Exchange 2000 Server Standard Edition, a warning is displayed.

Exchange store databases on Exchange Server 2003 Standard Edition and Exchange 2000 Server Standard Edition cannot grow larger than 16 GB. After that limit is reached, the mailbox store will no longer mount and Exchange will be inaccessible. Exchange store databases in Exchange Server 2003 Enterprise Edition and Exchange 2000 Server Enterprise Edition are not limited to 16 GB; they are limited only by available hardware, with a theoretical maximum size of 16 terabytes.

To correct this warning

  1. Consider moving some of the mailboxes from the large mailbox store to a new mailbox store on this or another Exchange Server computer.

  2. If you have recently moved mailboxes from this information store to another store, or if you have recently deleted mailboxes from this mailbox store, performing an offline defragmentation may decrease the size of the files.

  3. Consider setting mailbox and message size limits to prevent unlimited growth of the mailbox store.

Note

With the release of Exchange Server 2003 Service Pack 2 (SP2), in Exchange Server 2003 Standard Edition, the hard-coded licensing database size limit has been increased from 16 GB to 75 GB. The administrator can set a protective database size limit (prevent unintentional database size growth). The default value is 18 GB in SP2 for Standard Edition and the default of 18 GB can be overwritten by editing the Database Size Limit in Gb registry key.

Important

This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore the registry if a problem occurs. For information about how to restore the registry, view the "Restore the Registry" Help topic in Regedit.exe or Regedt32.exe.

To configure the database size limit for a database with Exchange Server 2003 SP2

  1. On the computer running Exchange Server, start Regedit.exe.

  2. Open the following registry key: HKLM\System\CurrentControlSet\Services\MSExchangeIS\Server name\Private-Mailbox Store GUID

  3. Right-click Private Store GUID, point to New, and then click DWORD Value.

  4. For the new value name, type Database Size Limit in Gb.

  5. Double-click Database Size Limit in Gb. In Value data, type an appropriate value for maximum database size in GB. For Exchange Server 2003 Standard Edition, type a decimal value between 1 and 75 (the default is 18 GB). For Exchange Server 2003 Enterprise Edition, type a decimal value between 1 and 8000 (the default is 8000 GB). Click OK.

  6. Right-click Private Store GUID, point to New, and then click DWORD Value.

  7. For the new value name, type Database Size Buffer in Percentage.

  8. Double-click Database Size Buffer in Percentage. In Value data, type a decimal value between 1 and 100 to specify when you want events to be logged to warn you that you are nearing the maximum size for a database. The default value of 10 will result in warning events to be logged when you have 10 percent capacity left before you reach the maximum size for that database. Click OK.

  9. Right-click Private Store GUID, point to New, and then click DWORD Value.

  10. For the new name, type Database Size Check Start Time in Hours From Midnight.

  11. Double-click Database Size Check Start Time in Hours From Midnight. In Value data, type a value between 0 and 23 to specify when you want Exchange to check the database size. The default value of 5 results in Exchange Server checking the database size 5 hours after midnight (5:00 AM). Click OK.

  12. Close Registry Editor.

Before you edit the registry, and for information about how to edit the registry, see the Microsoft Knowledge Base article 256986, "Description of the Microsoft Windows Registry" (https://go.microsoft.com/fwlink/?linkid=3052&kbid=256986).

For more information about .stm and .edb files, see the Microsoft Knowledge Base article 232323, "Native Content Storage in Microsoft Exchange" (https://go.microsoft.com/fwlink/?LinkId=3052&kbid=232323).

For more information about moving mailboxes in Exchange Server 2003, see the Knowledge Base article 821829, "Moving Mailboxes in Exchange Server 2003" (https://go.microsoft.com/fwlink/?LinkId=3052&kbid=821829).

For more information about moving mailboxes in Exchange 2000 Server, see the Knowledge Base article 328810, "Moving mailboxes between servers" (https://go.microsoft.com/fwlink/?LinkId=3052&kbid=328810).

For more information about performing an offline defragmentation of an Exchange Server database, see the Knowledge Base article, 328804, "How to Defragment Exchange Databases" (https://go.microsoft.com/fwlink/?linkid=3052&kbid=328804).

For more information about setting message size limits, see the Knowledge Base article 322679, "Set Size Limits for Messages" (https://go.microsoft.com/fwlink/?linkid=3052&kbid=322679).

For information about Exchange Server 2003 Standard Edition or Microsoft Exchange 2000 Server Standard Edition reaching the maximum database size, see the Knowledge Base article, 828070, "Exchange Server Mailbox Store Does Not Mount When the Mailbox Store Database Reaches the 16-GB Limit" (https://go.microsoft.com/fwlink/?linkid=3052&kbid=828070).

For more information about SP2 for Exchange Server 2003, see the Exchange Server 2003 Service Pack 2 Web site (https://go.microsoft.com/fwlink/?LinkId=52073).