I) Introduction:

        **************************************************************************************
	WARNING: THIS SCRIPT WILL REQUIRES THAT /etc/sysconfig/initiator FILE NOT EXIST.

	WARNING: THIS SCRIPT DEPENDING ON CONFIGURATION WILL ISSUE WRITES TO THE ISCSI LUN IN QUESTION.

	WARNING: DO NOT RUN THIS SCRIPT IN A PRODUCTION ENVIRONMENT.  THIS SCRIPT IS USED TO PERFORM
	DOMAIN VALIDATION ON ISCSI TARGET NODE ENDPOINTS WITH INCREMENTAL COMBINITIONS OF RFC-3720
	PARAMETER KEYS.  PLEASE SEE SECTION 12 OF THIS RFC FOR MORE INFORMATION OF MEANING OF SAID KEYS.

        Each time the script is invoked for passed iSCSI channel, it will perform login/logout
	based on the number of iterations from the enabled keys.  Upon a successful establishment
	of an iSCSI nexus an validation using the determine configuration, a userspace program wil
	be run on the block device translated from the Channel+LUN tuple (ie: /dev/sd*).  The ordering
	of the enabled keys is located in main loop of core-iscsi-dv.sh.  It will halt the execution of
	the next nexus configuration when any non-zero status event occurs.
        **************************************************************************************

II) core-iscsi-dv.sh usage:

	Runs defined combinitions of traditional iSCSI (RFC-3720) parameters by generating
	core-iscsi /etc/sysconfig/initiator.  It will then start/stop from a passed
	iSCSI Initiator Channel from /etc/sysconfig/initiator until an exception or otherwise
	non-successful start/stop.  Once the session has been established, the script will
	can call various CLI tools to perform IO on the block device and return status.
	Currently two dd_read and surface_test routines defined.

	The iSCSI connection count for the established nexus is currently hardcoded to CONN_COUNT=1
	This value can be changed for target nodes supporting MC/S.  The usage of this script with
	target nodes that DO NOT support MC/S is undefined and untested.

	An known bug exists with MaxRecvDataSegmentLength in core-iscsi v1.6.2.x, please refer to
	http://groups.google.com/group/Core-iSCSI/browse_frm/thread/a0b66ade9417b738/79c039a6a2f7a940

	Support for value-lists of FIM in A.1 of RFC-3720 has TODO status.

    A) Usage:

	/sbin/core-iscsi-dv.sh $ISCSI_CHANNEL $ISCSI_LUN

	The CHANNEL needs to be uninitialized, and perferrable the iscsi_initiator_mod.ko
	module unloaded before invoking the script.

	If /etc/sysconfig/initiator exists when the script is invokead an exception will occur.
	Please backup and remove your /etc/sysconfig/initiator if you wish to use core-iscsi-dv.

    B) Enabling/disabling parameter keys:

	The default usage (2k loop iterations):

	 cat /sbin/core-iscsi-dv.sh | grep _enable=
	 DefaultTime2Wait_enable=0;
	 DefaultTime2Retain_enable=0;
	 HeaderDigest_enable=1;
	 DataDigest_enable=1;
	 MaxRecvDataSegmentLength_enable=1;
	 ErrorRecoveryLevel_enable=0
	 IFMarker_enable=0 # TODO
	 OFMarker_enable=0 # TODO
	 IFMarkInt_enable=0 # TODO
	 OFMarkInt_enable=0 # TODO 
	 DataPDUInOrder_enable=0
	 DataSequenceInOrder_enable=0
	 FirstBurstLength_enable=0
	 MaxBurstLength_enable=0
	 MaxOutstandingR2T_enable=0
	 ImmediateData_enable=0
	 InitialR2T_enable=0

	Additional upper-limit values can be defined for keys that accept a numerical value:

	 cat /sbin/core-iscsi-dv.sh | grep _end=
	 DefaultTime2Wait_end=65536;
	 DefaultTime2Retain_end=65536;
	 MaxRecvDataSegmentLength_end=262144;
	 ErrorRecoveryLevel_end=2
	 FirstBurstLength_end=262144
	 MaxBurstLength_end=262144
	 MaxOutstandingR2T_end=16

Thanks! -- nab@kernel.org