Admin Tip #158: Windows NT detects only eight logical units on SCSI device

Hits: Failed to execute CGI : Win32 Error Code = 3

Modern SCSI controllers support many logical units (LUs). By default NT will only detect the first eight LUs on a scsi controller unless the parameter value DevicenLargeLuns has been set for the driver of the scsi card where n is the scsi bus number. For the Adapter2940 which Dell widely uses:

Hive: HKEY_LOCAL_MACHINE
Key: SYSTEM\CurrentControlSet\Services\aic78xx\Parameters
Name: Device0LargeLuns bus 0
Name: Device1LargeLuns bus 1
Type: REG_DWORD
Value: 1 enable

After setting DeviceLargeLuns for the appropriate bus, the SCSI will detect whatever the number of LUs supported.