Bus Reset


The BUS RESET condition is where the device has been reset typically by some communication or electrical fault either on the SCSI BUS, in the PC, in the power being supplied to the library or PC or in some cases within the library itself. (This can even occur when the drive attempts to mount a physically damaged piece of media.)


This places the device in an invalid state where it no longer responds to normal SCSI commands. This condition is as if someone had quickly powered the device on and off. Communication via ASPI is terminated.


This is a device level, subsystem error.


Once this error occurs you will need to shutdown the Windows server, and cycle the power for the library. You will then power on the library to a ready state and then restart Windows and then InveStore.


One time occurrence:


In some cases the BUS RESET error can be an isolated event, due to a glitch or sub-system problem. You might review your Windows event logs (system and application) to see if the operating system notes any issues that you need to look into.


Is this the first time you have encountered this error, or is this a repeating pattern? If this is a one time occurrence you should shutdown InveStore, shutdown Windows, and power off the library.


Turn back on the library and execute an "initialize element status" (for HP) or the "Scan elements" (for Plasmon) test (please refer to your library users manual). If this passes then restart Windows and InveStore. If it fails, then you will need to contact the library vendor for assistance.


Repeating pattern:


If however the Bus Reset errors are a repeating pattern, then you will need to trouble shoot the hardware to determine which part of the SCSI BUS is causing the error. Make sure that both your library, and storage server are on a UPS. This will protect these systems from power instability that can cause the RESET to occur.


Also make sure that you are under the SCSI specification for both your storage device and the SCSI card you are using. You should verify that the following components are functioning properly:



      SCSI cable

      SCSI card.


Other considerations:


      Consider using a shorter SCSI able.

      Is your Windows server seeing any other problems during normal operations?

      Are the Windows event logs (system and application) showing any SCSI/ASPI errors, or other potential conflicts?

      If you have a separate PC server for a test, you may set the library up on this system and retry using InveStore.

      You may also consider contacting the manufacturer of your library and discuss with them the Sense key information (06, 29, 00 shown above) that the device reported. Ask for their recommendations as to what fault in the library may be causing the BUS RESET condition.


It is important not to be too quick to jump to conclusions about library responsibility for these Bus Reset errors, until all of the analysis has been completed. You will first need to trouble shoot your server to make sure that this is not a PC/server issue.


In some cases, it may be necessary to use a device such as a SCSI Analyzer to assist with the debugging of the problem. This device attaches to the SCSI Bus, and traps communication between the SCSI card and the storage device during normal production operations. It can provide additional information to the hardware people so that they may isolate the problem component.