Consider the following scenario:

  • You use Microsoft iSCSI Initiator to connect to an iSCSI target from a computer that is running Windows Vista or Windows Server 2008.
  • An iSCSI Protocol Data Unit (PDU) is rejected by the target for one of the reasons that are outlined in section 10.17.1 of iSCSI Specification Request for Comment (RFC) 3720.

In this scenario, iSCSI Initiator should resend the PDU that was rejected by the iSCSI target. However, iSCSI Initiator may be unable to communicate with the iSCSI target for several minutes.

Specifically, iSCSI Initiator cannot communicate with the target for a period of five times the Disk Timeout value that is specified in the following registry entry:

Subkey: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Disk
Entry: TimeoutValue
Value: The Disk Timeout Value in seconds

After a period of five times the Disk Timeout Value elapses, iSCSI Initiator performs session recovery, and then the iSCSI session is dropped and reestablished. Eventually, iSCSI Initiator may be able to communicate with the iSCSI target again.

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