Date: January 31, 1992 X3T9.2/92-030 To: X3T9.2 Membership From: Lawrence J. Lamers, X3T9.2 Secretary Subject: January 27-28, 1992 SPP Working Group Meeting Minutes The meeting convened at Apple Computer at 9:00 am on January 27, 1992. The meeting was hosted by Scott Smyers. A specific agenda was not established for this meeting. This SPP working group meeting was intended to address document content and structure. The items discussed at this meeting were: 1. SCSI-3 Document Structure Model 2. SCSI Architecture Model Document Elements 3. Elements for Protocol layers and for Common Document 4. Command Set Documents 5. SIP Document Elements 6. Dynamic Multi-path 7. Adjournment The following people attended the meeting: Name Organization ------------------------------ ------------------------------ Mr. Percy R. Aria Advanced Micro Devices Mr. Scott Smyers Apple Computer Mr. Ramiro Calvo Apple Computer Mr. Edward A. Gardner Digital Equipment Corp. Mr. Charles Monia Digital Equipment Corp. Mr. I. Dal Allan ENDL Mr. Kurt Chan Hewlett Packard Co. Mr. Eric Tausheck Hewlett Packard Co. Mr. George Penokie IBM Corp. Mr. Gary R. Stephens IBM Corp. Mr. Lawrence J. Lamers Maxtor Corp. Mr. John Lohmeyer NCR Corp. Mr. Robert N. Snively Sun Microsystems, Inc. Results of Meeting 1. SCSI-3 Document Structure The following figure illustrates the SCSI-3 document structure that evolved during the meeting. It splits the SCS and SPP documents into several new documents which, if accepted, will require additional project proposals. +------------------+ +------------------+ | SCSI-3 Block | | SCSI-3 Stream | o o o | Commands (SBC) | | Commands (SSC) | +------------------+ +------------------+ | | +----------------------------------------------------------------------+ | SCSI-3 Common Commands (SCC) | +----------------------------------------------------------------------+ | +----------------------------------------------------------------------+ | SCSI-3 Architecture Model (SAM) | +----------------------------------------------------------------------+ | | | | +-------------+ +-------------+ +-------------+ +-------------+ | SCSI-3 | | SCSI | | Serial | | Generic | | Interlocked | | Fiber | | Bus | | Packetized | | Protocol | | Channel - 4 | | Protocol | | Protocol | | (SIP) | | (FC-4S) | | (SBP) | | (GPP) | +-------------+ +-------------+ +-------------+ +-------------+ | | | | o o o +-------------+ +-------------+ +-------------+ +-------------+ | SCSI-3 | | | | IEEE | | | | Parallel | | Fiber | | P1394 | | All | | Interface | | Channel | | Serial | | | | (SPI) | | (FC-PH) | | Bus | | | +-------------+ +-------------+ +-------------+ +-------------+ Partial consensus was reached that we standardize on a normative packet structure that can be used by any of the serial links. The elements are a packet for command, one for data and one for response. The command packet contains the cdb, data length, direction, queue control, and the internal nexus id. The data packet contains the media. The response packet contains the status and sense information. The bit level details of the command packet were not fully agreed upon. 2. SCSI Architecture Model (SAM) Document Elements The following cryptic notes were collected during the discussion of what should be in the SAM document: Items for Common Layer - a model will be developed by Gary Stephens - CDB template - status - sense - queuing model - nexus info - reset, abort, terminate - invalid lun - unexpected reselect - rounding - asynchronous event notification - contingent allegience & eca - packet structure - parts of 6 & 7 Sections for SAM Document from SCSI-2 index: 6.1 Command Implementation Requirements. . . . . . . . . . . . . . . . . 72 6.1.1 Reserved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 6.1.2 Operation Code Types . . . . . . . . . . . . . . . . . . . . . . . 72 6.2 Command Descriptor Block . . . . . . . . . . . . . . . . . . . . . . 73 6.2.1 Operation Code . . . . . . . . . . . . . . . . . . . . . . . . . . 74 6.2.2 Logical Unit Number. . . . . . . . . . . . . . . . . . . . . . . . 75 6.2.3 Logical Block Address. . . . . . . . . . . . . . . . . . . . . . . 75 6.2.4 Transfer Length. . . . . . . . . . . . . . . . . . . . . . . . . . 75 6.2.5 Parameter List Length. . . . . . . . . . . . . . . . . . . . . . . 76 6.2.6 Allocation Length. . . . . . . . . . . . . . . . . . . . . . . . . 76 6.2.7 Control Field. . . . . . . . . . . . . . . . . . . . . . . . . . . 76 6.3 Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 6.5 Command Processing Considerations and Exception Conditions . . . . . 81 6.5.1 Programmable Operating Definition [move to CHANGE DEFININTION] 6.5.3 Selection of an Invalid Logical Unit . . . . . . . . . . . . . . . 82 6.5.4 Parameter Rounding . . . . . . . . . . . . . . . . . . . . . . . . 83 6.8.3 Example of Queued I/O Process [move to ANNEX 'x' of each protocol document] 6.8.3.1 Typical Sequences for Tagged Queuing [move to ANNEX 'x' of each protocol document] 6.8.3.2 Example of Tagged Queuing [move to ANNEX 'x' of each protocol documen] 3. Elements for Protocol layers and for Common Document These items need to be dealt with in the SAM document and the protocol documents (e.g., SIP, GPP, SBP, FC-4S). Exception conditions: - Unexpected connections - Incorrect initiator connection - unexpected reselection - reset: device, single, multi, transport - abort, abort I/O process, single, multi - clear queue - terminate I/O process - error reporting: CA, ECA, Sense, Link - event notification: AEN, Unit Attention Generic topics: - queueing - multi-porting - multi-pathing - I/O process identification: nexus, address - Explicit data length and data direction - packet structure command: cdb, data length, direction, queue control, internal nexus id data: media response: status, sense information 4. Command Set Documents Division of the SCS documents: - block device command set 8, 12,13,15 - stream device command set 9,10, 11, 17 - scanner device command set (IT-8 WG 14) - medium changer command set - SCSI Common Commands Document The SCC document contains the commands in SCSI-2 section 7, and may contain other commands if agreed to. 5. SIP Document Elements The following items were agreed to be in the SIP document Sections for SIP from SCSI-2: 6.4 Command Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 79 6.4.1 Single Command Example [move to ANNEX A of each Protocol Document] 6.4.2 Disconnect Example [move to ANNEX B of SIP] 6.4.3 Linked Command Example . . . . . . . . . . . . . . . . . . . . . . 80 6.4 Command Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 79 6.4.1 Single Command Example . . . . . . . . . . . . . . . . . . . . . . 79 6.4.2 Disconnect Example . . . . . . . . . . . . . . . . . . . . . . . . 79 6.4.3 Linked Command Example . . . . . . . . . . . . . . . . . . . . . . 80 6. Dynamic Multi-path, Data Length Gary Stephens was strongly in favor of adding support to SAM for dynamic multi-pathing. This was opposed by almost everyone. The agreement is to allow a transport specific field in SAM, which could be used to support dynamic multi-pathing. The objective is to get the hooks into the architecture; whether or not it is an appropriate item for standardization is in question. There was a series of discussions on what information should be in the command packet. There was considerable debate on the addition of some fields to the SCSI command sequence (e.g., CDB length, multi-pathing) in the SCSI FC-4. This issue relates to all the other interface variants. 7. Adjournment The meeting adjourned at 5:00 pm on Tuesday January 28, 1992.