Promise Technology M500p, M500i, M500f, M300p Connection Problems, Scsi Connections, Termination

VTrak M-Class Product Manual

Connection Problems

When you install your Promise product following the instructions in the Quick Start Guide and this Product Manual, you should have little trouble getting your equipment to work the first time. But connection problems can arise that are not the User's or Installer's fault. Every conceivable problem cannot be covered in the documentation but some guidelines could be helpful.

Connection problems cause a majority of failures in almost any electrical system. While the installation of the cables and components was correct, they don't function properly, or at all, because:

•A connector is dirty or corroded

•A connector is loose or damaged

•A cable looks OK outside but has an open circuit inside

•The wrong cable was used

VTraks ship with a full set of new cables, as required for each specific model. Be sure to use these components because: 1.) They are the proper ones for your RAID subsystem, 2.) They are in brand-new condition, and 3.) You paid for them with the purchase of your VTrak.

SCSI Connections

VTrak uses a network connection to pass command and management information. Data is transmitted via the SCSI bus. Proper termination and SCSI-3 compliant cables are required for the system to operate correctly.

SCSI connections are both physical (outside) and electrical (inside). You can see a physical connection, you can clean it or try a different cable on it. Electrical connections are made by firmware and software.

VTrak makes use of SCSI Target IDs (TIDs) and Logical Unit Numbers (LUNs) to enable multiple VTrak arrays managed by a single Host PC

SCSI channels are completely intolerant of TID conflicts. If you have a conflict, the devices on your SCSI chain will not work correctly until it is resolved.

The VTrak RAID subsystem is sensitive to the presence of other devices on the SCSI chain. Do not connect other devices to the SCSI chain with a VTrak, except for an other VTrak.

Termination

VTrak has an internal termination feature but it works only on the “Out” connector. Internal termination is set to “Automatic” by default. For termination settings, see “SCSI Channel Settings” on page 95 or “Channel Settings” on page 198.

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