SCSI Primary Commands - 2.pdf

18 July 2001 T10/1236-D Revision 207.2 EXTENDED COPY command7.2.1 EXTENDED COPY command introductionThe EXTENDED COPY command (see table 14) provides a means to copy data from one set of logical units toanother set or to the same set of logical units. The entity within a device server that receives and performs theEXTENDED COPY command is called the copy manager. The copy manager is responsible for copying data fromthe source device(s) to the destination device(s). The copy source and destination devices are logical units thatmay reside in different SCSI devices or the same SCSI device. It is possible that all the SCSI devices and the copymanager are the same logical unit.Table 14 — EXTENDED COPY commandBitByte7 6 5 4 3 2 1 00 OPERATION CODE (83h)1 Reserved2 Reserved3 Reserved4 Reserved5 Reserved6 Reserved7 Reserved8 Reserved9 Reserved10 (MSB)1112PARAMETER LIST LENGTH13 (LSB)14 Reserved15 CONTROLBefore the copy manager is instructed to move data, the application controlling the data movement shall independentlytake any necessary actions required to prepare the source and destination devices for the EXTENDEDCOPY command. These actions may include media changer commands, loading of tapes, MODE SELECTcommands reservation commands, positioning of tape, etc. After all preparatory actions have been accomplished,the EXTENDED COPY command should be issued to the copy manager to start the data transfer.The PARAMETER LIST LENGTH field specifies the length in bytes of the parameter data that shall be contained in theData-Out Buffer. A parameter list length of zero indicates that copy manager shall not transfer any data or alter anyinternal state; this shall not be considered an error. If the parameter list length causes truncation of the parameterlist in a target descriptor or segment descriptor, no data shall be transferred and the EXTENDED COPY commandshall be terminated with a CHECK CONDITION status. The sense key shall be set to ILLEGAL REQUEST and theadditional sense code shall be set to PARAMETER LIST LENGTH ERROR.dpANS SCSI Primary Commands - 2 (SPC-2) 43