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Optimum SCSI configuration and troubleshooting for high performance tape drives
(KB # 5A9D11E0)


Failed backups due to SCSI bus instability. Errors located in the System log of Windows event viewer:

  • -Parity errors (Windows Event ID 5)
  • -Data Phase errors (Windows Event ID 5)
  • -Device timeouts (Windows Event ID 9)
  • -Controller errors (Windows Event ID 11)
  • -Device not ready for Access (Windows Event ID 15)
  • -SCSI Bus Reset (Windows Event ID 117)
  • -Overloaded SCSI bus
  • -Old SCSI HBA drivers
  • -RAID enabled controllers
  • -Incompatible or malfunctioning SCSI card
  • -Conflicting SCSI ID's
  • -Bad cable(s) and/or terminator(s)

It is our experiance that swapping the SCSI cable(s) for new is the most common fix for SCSI I/O issues.


While having any combination of these
-Ultra160/Ultra320 SCSI Card

-Latest BIOS
-Latest drivers
-Don’t share IRQ if at all possible
-Disable HostRAID or any other RAID capability if so equipped
-Disable Domain Validation
-Ultra160/Ultra320 cabling
-LVD/ Ultra160/Ultra320 Active Terminator


-Latest firmware on both
-Latest drivers from software provider (or as recommended by software provider)
-No more than two drives per SCSI bus*
-Library: ID 2
-Drive 1: ID 3
-Drive 2: ID 4

* LTO-3 tape drives are Ultra160 devices. To put more than one drive on the bus you would require an Ultra320 controller to ensure there is enough bandwidth to run both drives simultaneously without running into bandwidth limitations.

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