SCSI Time-Out Error Messages with EMC Symmetrix Disk Arrays (248191)

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256986 Description of the Microsoft Windows Registry

SYMPTOMS

If you use Windows NT 4.0-based or Windows 2000 Server-based servers using EMC Symmetrix disk arrays, you may log SCSI time-out errors during the online upgrades and reconfiguration operations.

Event Viewer Example:
Event ID: 9
Source: EMC_Driver_name
Description: The device, \Device\ScsiPort0, did not respond within the timeout period.

CAUSE

EMC's Symmetrix disk array supports on line upgrade and reconfiguration operations that require stalling I/O operations at certain points during the operation. If these operations are carried out while the Symmetrix array is under load, the I/O stall may last longer than the default 10 second time-out value that Windows NT 4.0 sets for SCSI operations. This timeout value is 20 seconds for Windows 2000.

RESOLUTION

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
To resolve this issue, add the TimeOutValue DWORD value in the following registry key. EMC recommends setting the value data to 60 seconds in decimal format.

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Disk\

This procedure is described in the Windows NT 4.0 DDK documentation release notes.

EMC's Hardware Compatibility testing for HCL certification is done with TimeOutValue set to 60 seconds.

MORE INFORMATION

Most computers do not need this registry value. If you have a mass storage device that is continually timing out on complex operations, you can use this registry value to set the time-out period to a slightly higher value. Make sure that the programs you use do not have time out logic, which might cause a problem if this value is reset. Consult your ISV or program provider before you change the SCSI timeout parameters.

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