The following are some troubleshooting tips to help diagnose and pinpoint
the problem:
- Read the SCSI controller manufacturer's technical manual to determine the termination requirements. Many modern SCSI controllers require active terminators (at least one of the devices on the bus must provide termination power). Proper termination involves both a terminator
(resistor) and a device that supplies a signal to the bus for termination power. The SCSI-2 standard specifies that a controller (initiator) must supply termination power. Therefore, any controller that claims to be SCSI-2 compatible probably does supply termination power, but you should check if you are unsure. Also, many devices, especially drives, give you the option of providing termination power; if you have a jumper on the drive that reads Trmpwr, you should enable this jumper.
- If both internal and external SCSI devices are attached, make sure the last device on each SCSI chain is terminated, and that intermediary
devices are not.
- If only a single SCSI chain is used (either all internal or external), ensure the last device of the SCSI chain is terminated and the SCSI controller itself is terminated. This is usually a BIOS setting.
- Check for loose or poor quality SCSI cabling. When you have a long
chain of cables with mixed internal and external cabling, you run the risk of degrading the signal. Even though the SCSI specification may specify a long distance, the specification assumes cabling that allows no leakage or interference, and the reality is generally a shorter distance. Whenever you have 6-foot or longer external cables, you should replace them with 3-foot cables.
- Note when the event messages are posted and try to determine if it
coincides with certain processing schedules (such as backups) or heavy
disk processing. This will help to determine what device may be causing
the errors.
Note The reason that drives tend to have these types of problems under heavy stress is often slow microprocessors. In a multitasking
environment, the processor may not be fast enough to process all the I/O commands that come in nearly simultaneously.
- Slow the transfer rate settings if the timeouts are associated with tape drives - using 5MBS transfer rate usually cures the timeouts.
- Simplify the SCSI/IDE chain by removing devices, or move the device in question to another controller. If the problem follows the device, you should replace it.
- Check the revision of SCSI controller BIOS and device firmware
revisions. Contact the manufacturer for the latest revisions. See the Checking the Model Number and Firmware Revision section below for the procedure on how to do this.
- Check the SCSI device drivers version. The SCSI driver is located
in the %Systemroot%\System32\Drivers directory. Look at the version in the file properties, and check whether the SCSI manufacturer has a newer version.
- Remove other controllers that may create bus contention problems.
- A low-level format performed by the SCSI controller may resolve these event messages.
- Use a different make or model of any suspect hardware.
Checking the model number and firmware revision
The model number of the device and firmware revision are in the Windows
registry. To check the model number and firmware revision, follow the steps
below.
Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
322756 How to back up and restore the registry in Windows
- Run Regedt32.exe.
- Locate and click the following registry key, where x varies according to device number:
HKEY_LOCAL_MACHINE\Hardware\Devicemap\Scsi\ScsiPortx\ScsiBusx\
TargetIdx\LogicalUnitIdx
- Look at the REG_SZ identifier value to see the model number and
firmware revision values. For example, in the following value, the firmware revision value is 0510:
SEAGATE ST32430N 0510
- Record all the device model numbers and firmware revisions, and check with the manufacturer for any known issues.
Note For Windows 2000 and Windows Server 2003, you can view model and firmware revisions for hardware under the following registry location:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum
For more information about troubleshooting these events, click the following article number to view the article in the Microsoft Knowledge Base:
259237
Troubleshooting event ID 9, 11, and 15 on cluster servers