SCSI Primary Commands - 2.pdf

T10/1236-D Revision 20 18 July 2001server shall return CHECK CONDITION status and shall set the sense key to ILLEGAL REQUEST with anadditional sense code of INVALID FIELD IN CDB.7.26.9 Write data to echo buffer (1010b)In this mode the device server transfers data from the application client and stores it in an echo buffer. An echobuffer is assigned in the same manner by the target as it would for a write operation. Data shall be sent aligned onfour-byte boundaries. The BUFFER ID and BUFFER OFFSET fields are ignored in this mode.NOTE 39 It is recommended that the target assign echo buffers on a per initiator basis to limit the number ofexception conditions that may occur in a multi-initiator environment.Upon successful completion of a WRITE BUFFER command the data shall be preserved in the echo buffer unlessthere is an intervening command to any logical unit in which case it may be changed.The PARAMETER LIST LENGTH field specifies the maximum number of bytes that shall be transferred from theData-Out Buffer to be stored in the echo buffer. The application client should attempt to ensure that the parameterlist length does not exceed the capacity of the echo buffer. The capacity of the echo buffer may be determined bythe BUFFER CAPACITY field in the READ BUFFER echo buffer descriptor. If the PARAMETER LIST LENGTH fieldspecifies a transfer in excess of the buffer capacity, the device server shall return CHECK CONDITION status andshall set the sense key to ILLEGAL REQUEST with an additional sense code of INVALID FIELD IN CDB.168 dpANS SCSI Primary Commands - 2 (SPC-2)