Troubleshooting Hardware and Network Problems

Identifying Problems After Installation

If the problem occurred after installation, it may indicate that the network was installed incorrectly.

• Check all network boards for possible conflicting address and I/O settings.

  Each component should be able to work as a standalone system. Remove all network boards in the server and boot DOS. Add each board one at a time and make sure that DOS still boots after each addition.

• Make sure that all cables are fastened securely to all network boards and network connectors, and that terminating resistors are installed correctly.

Resolving Hard Disk Access Problems

To diagnose hard disk access problems, you should identify if the following conditions exist:

• The disk driver has not been loaded.
• A hard disk is not installed or cabled correctly.
• The communication channel between the controller interface board, the disk coprocessor board, and the hard disk is not functioning.
• The hard disk controller board is not terminated or addressed correctly.

To resolve hard disk access problems, you should perform the following actions:

• Make sure the disk driver is loaded. At the console, type MODULES to view the loaded disk drivers.
• Check the cables between the hard disks and the controller boards. Be sure Pin 1 of each cable is attached to Pin 1 of each connector.
• Check the power cables and make sure they are seated correctly in the power sockets on the hard disks.
• Check the jumper settings on the disk coprocessor board (DCB), the controller board, and the hard disk. Refer to the hardware documentation for correct jumper settings.
• If you are using a DCB, run DISKSET to make sure the hardware configurations contained on the EEPROM chip on the disk coprocessor board match those for the hard disks in your server.
• Load INSTALL to check the NetWare disk partition and volume information on the hard disk. For details, see Maintaining Volumes.
• Make sure that each controller interface board connected to the same disk coprocessor board has its own valid address.

Making Computer Memory Available for Network Drivers

To increase the amount of workstation memory available for network drivers:

• Add more memory.
• Unload unneeded TSR (terminate-and-stay-resident) programs (DOS clients only).
• Modify the NET.CFG file to load only necessary drivers.
• Modify the CONFIG.SYS file to load only necessary drivers.

For more information about freeing up memory on a workstation, see Resolving Workstation Memory Problems.

For information about freeing up memory on a server, see Resolving Server Memory Problems.

Resolving Cabling Problems

• Use the proper cabling for your network topology as specified by IEEE. Make sure cable segments do not exceed the recommended lengths.
• Make sure cable segments are properly terminated for the type of cabling being used.
• Make sure terminators and in-line cable connectors are working properly.

  If you are not sure whether a terminator or connector is working properly, replace it. If the new components work properly, discard the old ones.

• Make sure there are no breaks in the cable or shield. Use a time delay reflectometer (TDR), a LANalyzer, or a volt ohm meter (VOM) to test cabling for breaks in the cable conductor or shield.
• Make sure cabling is routed away from devices that produce high electric or magnetic fields, such as fluorescent lights, microwaves, radar, X-rays, copy machines, etc.

Power Supply Errors

An inconsistent power source is the most common cause of hardware problems. It also produces the most devastating results.

Power outages cause workstations, network servers, print servers, and backup devices to reboot. When this happens, all information stored in RAM is lost, and sometimes hardware is damaged.

Power spikes and brownouts can also cause a variety of hardware errors.

You can have reliable network performance only if you plan for power outages and fluctuations and protect against them. The following tips can help you do this:

• Add a dedicated power feed and ground line from your breaker box to critical equipment. Make sure the ground line connects to earth ground.
• Install an uninterruptible power supply (UPS) or a standby power system (SPS) to provide power to critical equipment for 15 minutes after a power outage.

  The capacity of such power supplies is limited, so you may not want to plug nonvital hardware (such as monitors or printers) into the UPS or SPS line.

• Train users to save data and log out of the network when the lights go out. Then you can bring down the NetWare server in an orderly fashion without forcing users off the system while the server is running on UPS or SPS power.
• Install a surge suppressor or power conditioner on all power lines that are used by computers. Many UPS and SPS devices already have this feature.
• Do not allow anyone to plug fans, printers, copy machines, vacuum cleaners, or other motor-driven appliances into the dedicated line or into any power line with computers.

  Insert dummy plugs into open outlets to prevent people from plugging such appliances into computer power sources.