Even though Exchange 2003 has been very stable for us, SP2 isalready installed on the test server here and I’ve been doing some reading todetermine how soon we’ll need to install it. The biggest positive I’ve foundyet is the increase in the mail database limit to 75GB on the Standard versionof Exchange 2003. This is a much-needed increase, and the only reason we’rerunning Exchange’s expensive Enterprise version is our need to accomodate hugeattachements from cour clients. I also have a personal client intelevision-services who will be thrilled to know their four users can now storevideo clips in exchange, instead of constantly archiving to one big folder onthe network.
The 75GB database limit isn’t setautomatically when SP2 is installed. After all, 75GB exceeds a lot ofexpectations of the Exchange server and the disk space on most older servers.Since so few admins read the documentation, they might miss this change andlock up their servers. The registry change below, can be set to anyvalue between 1 and 75, the maximum size of the Exchange database in GB’s. Bydefault Exchange 2003 SP2 pushes the default database size to about 18GB, whichis the original 16GB maximum plus a 10% over-limit buffer to keep mail comingin while Exchange floods the system with alerts about the database size.
To expand the Exchange database, orset a limit between 1 & 75GB:
1: Open regedit and navigate to HKLM\SYSTEM\CurrentControlSet\Services\ MSExchangeIS\SERVER_NAME\Private-STORE_GUID
To change the Public store limit, navigate to HKLM\SYSTEM\CurrentControlSet\Services\ MSExchangeIS\SERVER_NAME\Public-STORE_GUID
2: In the event your Exchange server has more than one private or public store the GUID of each store can be found by running ADSIEDIT.msc and navigating to:CN=MAILBOX_STORE_NAME(SERVER_NAME),CN=STORAGE_GROUP_NAME, CN=InformationStore,CN=SERVER_NAME, CN=Servers,CN=FirstAdministrative Group,CN=Administrative Groups,CN=Organization name,CN=MicrosoftExchange,CN=Services,CN=Configuration,DC=domain,DC=com
SERVER_NAME,STORAGE_GROUP_NAME, and MAILBOX_STORE_NAME reflect the mail store to bechanged. Then take note of the objectGUID:… value for that mail store.
3: Create a new REG_DWORD value in the registry key for the correct GUID. Name it “Database Size Limit in Gb” and set the value from 1 to 75. 4: Assuming you are newly setting the “Database Size Limit in Gb” value, it will be detected at the next size check. Reboot the Information Store service for immediate recognition.
By setting the “Database Size Limitin Gb” key the mailbox store will not exceed that value. When the mail storereaches 90% off that value, a default 10% buffer is allowed, it will begin tolog event ID #9689 to notify you that the store limit has been reached.
Oncethe mail store does reach the maximum limit the first size check, which happensevery 24 hours at 5am, will not take the database offline. The second sizecheck will dismount the store that exceeds the limit.
Both the % of the mail store used asa buffer and the time of the database size check can be changed within the sameGUID registry key referenced above.
To set either, create a REG_DWORD valuenamed “Database Size Buffer in Percentage” or “Database Size Check Start Timein Hours From Midnight”.
Set their values from 1 to 100 or 0 to 23 to change,respectively, the buffer % or the offset from midnight for the size check.
The Exchange 2003 Enterpriseinformation store can also be limitted by the “Database Size Limit in Gb” key.
The valid range of values is 1 to 8000. If the key is not set, the defaultvalue is 8000GB.
It still amazes me that the ExchangeSystem Manager doesn’t have settings for either “max. database size” or “min.disk space remaining on server”.
Isn’t that the whole point of Exchange? …thatit’s faster and easier to run because it doesn’t require the amount ofexperience and forethought that Postfix does.
Update: This same registry tweak is also supported on Windows SmallBusiness Server 2003 (SBS). See the comments below for a link the the SBS 2003FAQ.
Thanks
Thursday, January 06, 2011
Anu
