ExchangeMTA Fails to Start If “MTAData” folder is on 2TB Physical disk

 

Recently I was involved in troubleshooting Exchange 2003 MTA Service, which failed to start after reboot . Two weeks early The storage team Extended the volume to 2.04TB which holds “MTAdata” Folder.

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If  extend the Physical disk , that contains "MTAData" Folder, MTA Service fails to recognize the single Disk size beyond 2 TB when it starts and 
Additionally following events are logged if you turn up diagnostic logging for MSExchangeMTA component.

Event Source: MSExchangeMTA
Event Category: Field Engineering 
Event ID: 9409
The Microsoft MTA registry parameter Max RPC Alloc Size is missing.  The default value will be used. [BASE MAIN BASE 1] (14)                                           

Event Source: MSExchangeMTA
Event Category: Field Engineering 
Event ID: 2096
An invalid configuration for low disk space handling has been detected on the disk where MTADATA is located.  Improper values are, Shortage threshold: 30 MB, Relief threshold: 40 MB. [BASE MAIN BASE 1 47] (16)                                                                                                                                                               

Event Source: MSExchangeMTA
Event Category: Resource 
Event ID: 9406
Description:
There is not enough Performance Monitor memory to display the MTA Connections information.  Stop attached Performance Monitors and re-start the MTA. [BASE MAIN BASE 1] (14)

So simple resolution would be :

1 - Allocate the smaller disk sizes , keep it below 2TB
2 - Follow the steps below and move "MTAData" folder to another volume with smaller size.
and change the "MTA Database" and the MTA "Run Directory" path.

  1. Stop the Microsoft Exchange MTA Stacks service. To do so, at the command prompt type the following command: net stop msexchangemta.
  2. Edit the following value to reflect the new location for the MTA Database Path (no change is required if you are not relocating the MTA Database Path): HKEY_Local_Machine\System\CurrentControlSet\Services\MSExchangeMTA\Parameters\MTA Database Path
  3. Edit the following value to reflect the new location for the MTA Run Directory (no change is required if you are not relocating the MTA Run Directory): HKEY_Local_Machine\System\CurrentControlSet\Services\MSExchangeMTA\Parameters\MTA Run Directory
  4. Explore the new path and make the new directory structure. You may omit the Mtacheck.out folder in the MTA Database Path because it makes this directory and runs later in this procedure.
    Important Explore the installation drive and make a backup copy of the exchsrvr\mtadata directory.
  5. Explore the original exchsrvr\mtadata directory.
  6. On the View menu, click Details, and again on the View menu, point to Arrange Icons, and then click by Type. Select and then move all of the *.dat files to the new MTA Database path. Change the security for the directory to match that of the original directory.
  7. Select all of the other files, and then move them to the new MTA Run Directory. Change the security of the directory to match that of the original directory.
  8. Delete the original exchsrvr\mtadata directory.
  9. At a command prompt, go to the exchsrvr\bin directory.
  10. Within the exchsrvr\bin directory, run mtacheck; the task should report "Database clean, no errors detected." You may have to run mtacheck again to receive this successful report message.
  11. Start the Microsoft Exchange MTA Stacks service. To do so, at the command prompt type the following command: net start msexchangemta.

More Information :

In past editions, Windows used 32-bit block numbers in the lower storage stack. This effectively limited support for single disk devices-which might be hardware RAID sets, sometimes called virtual disks or LUNs-to being no larger than 2 terabytes (TB). Exchange components was tested for this LUN size. RAID1 is limited to 2 TB. The use of Volume Manager sets, however, imposes a performance penalty and can make some storage management scenarios difficult or impossible.
for more information on Exchange MTA Service refer to following TechNet:
http://technet.microsoft.com/en-us/library/aa997788(EXCHG.65).aspx