Adding New SCSI Controller to DEC Alpha May Prevent Startup (175649)

SYMPTOMS

If you add a SCSI controller to an existing Microsoft Windows NT installation on a Digital Alpha Personal Workstation 433, the BIOS may not find the operating system boot partition.

This problem may also occur on other Alpha systems.

CAUSE

In some cases it may be necessary to add additional SCSI controllers to an existing system. Some of examples might be to add hardware for additional disk storage or to prepare for installing Microsoft Cluster Server, for example, which requires a separate SCSI bus for shared storage between cluster nodes.

Even though the boot device has not changed and the system BIOS indicates the correct device path to the boot device, it does not have the correct SCSI channel number stored for the path. This number is not displayed through the bios configuration menus.

RESOLUTION

To resolve this condition, reselect the device path for the boot and operating system partitions. This action will internally set the correct bus number for the boot device, which may have changed. This problem may be avoided by installing Windows NT with both controllers installed, rather than adding the additional controller at a later date.