NAS configuration problem

[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]  

Topic Last Modified: 2005-11-18

The Microsoft® Exchange Server Analyzer Tool queries the Active Directory® directory service to determine the value for the msExchESEParamLogFilePath attribute of each storage group object. This attribute specifies the location of the transaction log files used by databases in the storage group.

The Exchange Server Analyzer also queries Active Directory to determine the count of the entries listed in the homeMDBBL attribute of each mailbox store. The count of this attribute represents the number of mailboxes on the mailbox store.

Additionally, the Exchange Server Analyzer also queries the Win32_Service Microsoft Windows® Management Instrumentation (WMI) class to determine the value of the Started key for the Microsoft Windows Storage Server 2003 feature pack service (wssexchmap). A value of False indicates that the Windows Storage Server 2003 feature pack service is not running on this Exchange server. A value of True indicates that the Windows Storage Server 2003 feature pack service is running.

If the Exchange Server Analyzer determines that the value for any msExchESEParamLogFilePath attribute starts with S:\{, and that the Windows Storage Server 2003 feature pack service is started on an Exchange Server computer with more than 1500 mailboxes, a warning is displayed.

Windows Storage Server 2003 is the Microsoft platform for NAS devices. The Windows Storage Server 2003 storage layout is recommended for use with Exchange Server 2003 and is somewhat different from the standard Exchange Server layout. The recommended configuration is to put the Exchange Server databases on Windows Storage Server 2003 and put the transaction log files on a local disk inside the Exchange Server computer.

Microsoft developed the Windows Storage Server 2003 feature pack for three specific types of workload:

  • Small workloads, for up to 250 mailboxes hosted by one Exchange Server connected to one Windows Storage Server computer. In this scenario, the recommended Windows Storage Server configuration is a 1 gigahertz (GHz) or faster processor, 512 megabytes (MB) of RAM, four SCSI or IDE/SATA disks configured as a RAID-5 volume, and two network interface cards (NICs): one for connection to the LAN and a private Gigabit Ethernet adapter for connection directly to the Exchange server. The Exchange databases are stored on the RAID-5 volume; transaction logs remain on the Exchange server's local RAID-1.

  • Medium workloads, with up to 750 mailboxes in one storage group, hosted by one Exchange Server and a single Windows Storage Server computer. In this configuration, the Windows Storage Server computer should have a pair of 1 GHz or faster processors, 1 gigabyte (GB) of RAM, six SCSI disks, and a pair of NICs. The disks should be configured as a 4-disk RAID-5 array for databases and a separate two-disk mirror set for the transaction logs.

  • Large workloads, with one or two Exchange Server 2003 servers hosting up to 1,500 mailboxes in two storage groups. In this configuration, the Windows Storage Server should have two 1 GHz or faster processors, 2 GB of RAM, and a total of 14 disks: 10 for a RAID 0+1 array to hold the databases and two sets of mirrored disks for transaction logs.

This warning indicates that the Exchange Server computer has been configured to use Windows Storage Server 2003 for storage. When using Windows Storage Server for Exchange Server data storage, it is recommended that fewer than 1,500 concurrent users access the Exchange Server.

To correct this warning

  • Do one of the following:

    • Move the transaction logs to a local disk in the Exchange Server computer

    • Move some of the mailboxes on this Exchange Server computer to another Exchange Server computer so that there are 1,500 or fewer mailboxes on the Exchange Server computer using Windows Storage Server.

For more information about using the Windows Storage Server 2003 feature pack with Exchange Server 2003, see the document, Managing Exchange Storage with the Windows Storage Server 2003 Feature Pack (

For further information, see the following additional resources: