Minutes of SCSI Working Group Meetings

John Lohmeyer John.Lohmeyer at symbios.com
Mon Jul 21 14:06:36 PDT 1997


* From the T10 (formerly SCSI) Reflector (t10 at symbios.com), posted by:
* John Lohmeyer <John.Lohmeyer at Symbios.com>
*
Minutes of SCSI Working Group Meetings in Colorado Springs, CO  T10/97-210r0

Accredited Standards Committee*
National Committee for Information Technology Standards (NCITS)

                                             Doc. No.: T10/97-210r0
                                                 Date: July 21, 1997
                                              Project:
                                            Ref. Doc.:
                                             Reply to: John Lohmeyer

To:         Membership of T10

From:       Ralph Weber, Secretary T10
            Larry Lamers, Vice-chair T10
            John Lohmeyer, Chair T10

Subject:    Minutes of SCSI Working Group Meetings
            Colorado Springs, CO -- July 15-16, 1997


                                  Agenda

1. Opening Remarks

2. Approval of Agenda

3. Attendance and Membership

4. EPI {Tuesday Morning}
   4.1 Load Compensation [Novak]
   4.2 REQ/ACK Glitch Filters [Ham]
   4.3 Latching and Counting [Novak/Ham]
   4.4 Initiator Monitoring of Bus Free [Williams]
   4.5 EPI Grounding Clauses [Ham/McSorley]
   4.6 Hot Plugging [Ham]
   4.7 EPI Summary

5. SCSI Protocol {Tuesday Afternoon}

6. Enclosure Profile Study Group {Wednesday Morning}

7. General Topics {Wednesday Afternoon}
   7.1 Addressing Model for SAM-2 (was REPORT LUNS Issue) (97-122r3) [Penokie]
   7.2 STS Review [Johansson]
   7.3 SCSI Socket/SSL Services (SSS) Review (97-201r0) [Parker]
   7.4 QErr Recovery in HAP (97-187) [Monia]
   7.5 Prevent Allow Medium Removal Issue (96-___) [Oetting]
   7.6 Should I/O be allowed to be asserted during SCAM Selections? (reflector
      messages) [Tony DeLaCruz]
   7.7 Warning/PFA ASC Reporting Selection (97-203) [Penokie]
   7.8 Naming of Dual-Clocking SCSI
   7.9 Persistent Reservations (97-218) [Snively]
   7.10 REPORT LUNs Command Requirement (97-219) [Oetting]
   7.11 SPI-2 Revision 12 Protocol Topics Review [Penokie]
   7.12 High-Availability Profile (HAP) [Milligan]

8. Meeting Schedule

9. Adjournment



                              Results of Meeting

1.    Opening Remarks

John Lohmeyer, the T10 Chair, called the meeting to order at 9:00 a.m.,
Tuesday July 15, 1997.  He thanked Symbios Logic for hosting the meeting.

As is customary, the people attending introduced themselves and a copy of the
attendance list was circulated.  Copies of the draft agenda and general
information on T10 were made available to those attending.

2.    Approval of Agenda

The draft agenda was approved with the following additions:

      4.2 REQ/ACK Glitch Filters [Ham]
      4.3 Latching and Counting (97-182) [Novak/Ham]
      4.4 Initiator Monitoring of Bus Free [Williams]
      4.5 EPI Grounding Clauses [Ham/McSorley]
      4.6 Hot Plugging [Ham]
      4.7 EPI Summary
      7.8 Naming of Dual-Clocking SCSI
      7.9 Persistent Reservations [Snively]
      7.10  SPI-2 Protocol Topics Review [Penokie]

The following agenda items were moved to a separate agenda for the SCSI
Protocol Study Group:

      5. SCSI Protocol {Tuesday Afternoon}
      5.1 CRC Attach (97-197) [Asami]
      5.2 Status/Message Simplification (97-198) [Asami]
      5.3 Quick Arbitrate & Select (97-199) [Kosco]
      5.4 Broadcast Command Packet (97-200) [Kosco]
      5.5 Comments on 97-198r0, Status/Message Simplification 997-205)
      [Lohmeyer]
      5.6 Higher Performance SCSI [Ham]

3.    Attendance and Membership

John reminded the group that attendance at working group meetings does not
count toward minimum attendance requirements for T10 membership.  He noted
that working group meetings are open to any person or organization directly
and materially affected by T10's scope of work.

The following people attended the meeting:

         Name          S        Organization         Electronic Mail Address
---------------------- -- ------------------------- -------------------------
Mr. Norm Harris        P  Adaptec, Inc.             nharris at eng.adaptec.com
Mr. Vincent Bastiani   A# Adaptec, Inc.             bastiani at corp.adaptec.com
Mr. Lawrence J. Lamers A  Adaptec, Inc.             ljlamers at ix.netcom.com
Mr. Tak Asami          V  Adaptec, Inc.             asami at itc.adaptec.com
Mr. Bill Gintz         V  Adaptec, Inc.             bgintz at corp.adaptec.com
Mr. Wally Bridgewater  V  Adaptec, Inc.             wally at eng.adaptec.com
Mr. Tom Schneider      V  Adaptec, Inc.             schneid at itc.adaptec.com
Mr. Michael Wingard    P  Amphenol Interconnect     mikwingard at aol.com
Mr. Ron Roberts        A  Apple Computer            rkroberts at aol.com
Mr. Charles Tashbook   P  Dallas Semiconductor      charles.tashbook at dalsemi.
                                                    com
Mr. Michael Smith      A  Dallas Semiconductor      mike.smith at dalsemi.com
Mr. Greg McSorley      P  Data General / Clariion   greg_mcsorley at dgc.ceo.dg.
                                                    com
Dr. William Ham        A# Digital Equipment Corp.   ham at subsys.enet.dec.com
Mr. Roger Cummings     P  Distributed Processing    cummings_roger at dpt.com
                          Tech.
Mr. Don Vohar          A  Fujitsu (FCPA)            dvohar at fcpa.fujitsu.com
Mr. Zane Daggett       P  Hitachi Cable             zdaggett at hcm.hitachi.com
                          Manchester,Inc
Mr. Kirk Rogers        A  Hitachi Cable             krogers at hcm.hitachi.com
                          Manchester,Inc
Mr. George Penokie     P  IBM Corp.                 gop at us.ibm.com
Mr. Dan Colegrove      A# IBM Corp.                 colegrov at us.ibm.com
Mr. Barry H. Wiley     V  IMP, Inc.                 bhwiley at impinc.com
Mr. Dean Wallace       P  Linfinity Micro           75671.3443 at compuserve.com
Mr. Louis Grantham     A  Linfinity Micro           lgdatcom at ix.netcom.com
Mr. Alan Littlewood    P  LSI Logic Corp.           alanl at lsil.com
Mr. Pete McLean        P  Maxtor Corp.              pete_mclean at maxtor.com
Mr. Edward A. Gardner  P  Ophidian Designs          eag at ophidian.com
Mr. Skip Jones         P  QLogic Corp.              sk_jones at qlc.com
Mr. James McGrath      P  Quantum Corp.             JMCGRATH at QNTM.COM
Mr. Richard Uber       V  Quantum Corp.             duber at tdh.qntm.com
Mr. Pat McGarrah       V  Quantum Corp.             pmcgarra at tdh.qntm.com
Mr. Gene Milligan      P  Seagate Technology        Gene_Milligan at notes.
                                                    seagate.com
Mr. Daniel (Dan) F.    A# Seagate Technology        daniel_f_smith at notes.
Smith                                               seagate.com
Mr. Gerald Houlder     A  Seagate Technology        Gerry_Houlder at notes.
                                                    seagate.com
Mr. Dave Guss          P  Silicon Systems, Inc.     dave.guss at tus.ssi1.com
Mr. John Lohmeyer      P  Symbios Logic Inc.        john.lohmeyer at symbios.com
Mr. Ralph O. Weber     A  Symbios Logic Inc.        roweber at acm.org
Mr. Frank Gasparik     V  Symbios Logic Inc.        frank.gasparik at symbios.com
Mr. Tracy Spitler      V  Symbios Logic Inc.        tracy.spitler at symbios.com
Mr. Andy Brown         V  Symbios Logic Inc.        andrew.brown at symbios.com
Mr. Bill Schmitz       V  Symbios Logic Inc.        bill.schmitz at symbios.com
Mr. Graeme             V  Symbios Logic Inc.        gwl at symbios.com
Weston-Lewis
Mr. Kevin Gingerich    O  Texas Instruments, Inc.   k-gingerich at ti.com
Mr. Paul D. Aloisi     P  Unitrode Corporation      aloisi at unitrode.com
Mr. Gregory Kapraun    V  Western Digital Corp.     kapraun at wdroc.wdc.com

45 People Present

Status Key:  P    -  Principal
             A,A# -  Alternate
             O    -  Observer
             L    -  Liaison
             V    -  Visitor
 
4.    EPI {Tuesday Morning}

4.1   Load Compensation [Novak]

Bill Ham had no new input on this topic and Vit Novak was unable to attend.
So, this topic was deferred to the next meeting.

4.2   REQ/ACK Glitch Filters [Ham]

There was a lengthy discussion on the topic of glitch filters, based on a
proposal from Bill Ham (97-215).  George Penokie demanded that glitch
filtering be made mandatory, but at somewhat reduced times from those in
Bill's proposal.  Two straw polls set the direction: 1) the working group
recommended (13-3) to include wording on glitch filtering in SPI-2; 2) the
working group recommended (12-2) that the wording be a recommendation and not
a mandatory requirement.

Dave Guss offered some exceptional wording for the philosophy of filtering.
He accepted an action to work with Bill Ham to revise the proposal.

4.3   Latching and Counting [Novak/Ham]

Bill Ham and Dave Guss presented a document prepared by Dave (97-216).  The
document started with tutorial information about how synchronous data
transfers are processed.  The tutorial was followed by a discussion of the
types of failures that can occur.  The group discussed the failure modes
briefly.

Dave's conclusions included the belief that counting REQs and ACKs is
beneficial only at the target.  This conclusion was news to the group and
required clarifying discussion.

4.4   Initiator Monitoring of Bus Free [Williams]

Jeff Williams reminded Bill Ham of a problem that needs to be included in the
EPI results of the latching and counting work.  The problem that concerned
Jeff is a case where an initiator assumed that the bus would go free after a
Disconnect message and failed to monitor the BSY signal thus missing a
transition to Status phase driven by the target.  The result was a hung bus.

4.5   EPI Grounding Clauses [Ham/McSorley]

Bill Ham reviewed the grounding text from EPI, submitted by Greg McSorley.  A
few changes were made as a result of the review.

4.6   Hot Plugging [Ham]

Bill Ham presented a figure showing the four stages of a connector mating
process.  Bill reviewed the four stages and the issues and mechanical concerns
associated with each one.

The group also discussed hot plugging timing concerns with the text in SPI-2
revision 12.  The main problem was the inability to verify conformance to the
requirements, as worded.  George Penokie agreed to add a note to the next
revision of SPI-2.

4.7   EPI Summary

Bill Ham expressed an intention to bring a complete EPI draft document for
discussion to the next meeting.

5.    SCSI Protocol {Tuesday Afternoon}

See the separate minutes for the SCSI Protocol Study Group in 97-211.

6.    Enclosure Profile Study Group {Wednesday Morning}

George Penokie announced that SCC-2 revision 2 is available in printed copy at
this meeting.  He informed the group that he is resolving comments from Ralph
Weber, which are editorial and would have been delivered as letter ballot
comments if not processed at this time.  George announced plans to process
SCC-
2 revision 3 via letter ballot toward first public review.  In the absence of
any objections, the working group recommended that T10 issue a letter ballot
on forwarding SCC-2 revision 3 toward first public review.

Rod DeKoning presented a proposal for development of a profile Technical
Report that would describe how SCC-2 and SES can be used for open, general
RAID storage management (97-217).  Gene Milligan asked for an explanation of
how the proposed work relates to the DMTF (Desktop Management Task Force).
The group discussed DMTF at length and concluded that the proposed profile
does not conflict with the DMTF activities, and might act as a new, important
input to DMTF work.

Rod's summary concepts were received positively by the group.  The process of
writing a project proposal for the technical report was discussed.  It was
decided that forwarding of the project proposal will not occur until the
September meeting.  A draft outline of the TR will be developed in the
interim, mostly to promote broader interest in the work.  It was agreed that
another study group meeting will be held on Wednesday morning of the general
working group meeting (10 September 1997).  The draft project proposal will be
distributed at least two weeks prior to that meeting.

      Chair's Note:  The Enclosure Study Group meeting was moved to
      Wednesday afternoon (10 September 1997) as the result of a request
      made at the T10 plenary meeting.

7.    General Topics {Wednesday Afternoon}

7.1   Addressing Model for SAM-2 (was REPORT LUNS Issue) (97-122r3) [Penokie]

George Penokie presented a proposal the net effect of which would be
incorporating the salient aspects of the SCC hierarchical LUN addressing
mechanisms in SAM-2 and SPC-2.  George accepted several changes to the
proposal.  George agreed to bring a revised draft of the proposal to the next
working group meeting.

7.2   STS Review [Johansson]

Peter Johansson was unable to attend the meeting and discussion of this topic
was deferred to the next meeting.

7.3   SCSI Socket/SSL Services (SSS) Review (97-201r0) [Parker]

Keith Parker presented a review of the current concepts in the SSS project,
97-
201.  A major thrust of the review as a proposal that the SCSI commands be
defined in terms of remote procedure calls.  Keith proposed the creation of
a second project to contain the remote procedure calls definitions.  Gene
Milligan and Bob Snively proposed that the upper layers of the proposed
bifurcated specification appear as an annex in the currently proposed
document.

The group discussed the concepts and advantages of socket services.  Issues
regarding the assignment of a device type and an embedded capability bit in
the Inquiry data also were discussed.  However, specific action was deferred
until a draft SSS document was available for review.

Keith agreed to prepare a draft SSS document for group consideration.  He felt
that the draft would not be available in time for the next committee mailing,
but hoped it would be available by the next meeting.

7.4   QErr Recovery in HAP (97-187) [Monia]

Charles Monia was unable to attend this meeting and this issue was deferred to
the next meeting.

7.5   Prevent Allow Medium Removal Issue (96-___) [Oetting]

Erich asked that this item be dropped from this and future agendas.

7.6   Should I/O be allowed to be asserted during SCAM Selections? (reflector
messages) [Tony DeLaCruz]

Gerry Houlder said that I/O signal should not be set during SCAM, but could
find no written requirement that I/O shall not be set.  John Lohmeyer proposed
that the SCAM Annex in SPI-2 be changed to include a requirement that I/O
shall not be set during SCAM.

Gerry Houlder and Jim McGrath said that a blanket statement does (or should)
exist that limits signal level changes to those specified in the standard.
The group struggled with the wording of a blanket statement, but Jim McGrath
and Larry Lamers expressed a strong belief that a blanket statement would
cause more confusion than it would resolve.  Larry felt that no change at all
might be the best resolution for the problem.

The only conclusion reached was that the discussion of this topic will be
dropped from the next agenda.

7.7   Warning/PFA ASC Reporting Selection (97-203) [Penokie]

George Penokie presented revisions 0 and 1 of a proposal to provide additional
reporting controls in the informational exceptions control mode page.  He
reviewed the history of the proposal and noted one additional change based on
discussions on the SCSI Reflector.  In the absence of any objections, the
group recommended that the Plenary accept 97-203r2 (the proposal presented, as
revised) for inclusion in SPC-2.

7.8   Naming of Dual-Clocking SCSI

The group agreed to defer the naming decision regarding clocking on the
leading and trailing edges of REQ and ACK pulses to STA.  (Chair's note: STA
decided to not create a name for this feature; they do not want to explain it.
I suggest T10 internally call it `double-edge clocking'.)

7.9   Persistent Reservations (97-218) [Snively]

Bob Snively presented three problems with the SPC text defining persistent
reservations (97-218r0).  The group asked Bob to move some of the concepts in
his proposal out of the clauses that are specific to persistent reservations
to the clause defining the general model for reservations, in effect making
some of the concepts common to both SCSI-2 (or regular) reservations and
persistent reservations.

Bob agreed to bring a new revision of the proposal to the next meeting.

7.10  REPORT LUNs Command Requirement (97-219) [Oetting]

Erich Oetting presented a proposal regarding when support for the REPORT LUNS
command is mandatory. The group discussed the proposal and made several
corrections.  In the absence of any objections, the working group recommended
that T10 accept the proposal, as revised, for inclusion in SAM-2 and SPC-2.

7.11  SPI-2 Revision 12 Protocol Topics Review [Penokie]

George Penokie lead the group in a review of the protocol topics in SPI-2,
formerly SIP.  He started the discussion by announcing that bus `phases' are
back and `service interfaces' are gone.  George accepted several corrections
for SPI-2 in the protocol clauses and agreed to provide a revised SPI-2
document for the next meeting.

George informed the group that he has heavily rewritten Annex C (SCSI Bus
Fairness Techniques) from the committee approved proposal document.  He asked
everyone to review Annex C carefully.

In addition, the following issues were identified for further consideration,
with the intent that they be specifically reviewed during the next meeting:

 a)    RE: editor's note 30; what is the real intent of 96-268 and how does
    that affect the current content of SPI-2?
 b)    Look at SAM to make sure that clause 11.5.4 correctly describes how to
    respond to task management functions.
 c)    What does Annex A apply to, who has to meet it's requirements?

George announced that an editorial review meeting is being planned for August
27 in San Jose, hosted by Unitrode.  This meeting may be changed to a
teleconference or both.  Contact George Penokie for details.

7.12  High-Availability Profile (HAP) [Milligan]

Doug Hagerman reported no progress on rewriting HAP.  Gene Milligan, George
Penokie, Ralph Weber, and Doug discussed when and how a queue should be frozen
in the presence of an error.  The SAM requirement for a single work queue per
logical unit (as opposed to a work queue per initiator per logical unit) was
discussed as it relates to the freezing of activities in the presence of an
error.

The group agreed that HAP will be reworded to reflect the SCSI-3 queuing model
with respect to handling of Contingent Allegiance.  In addition, Gene Milligan
will prepare a proposal that expands the handling of errors in SCSI-3 to allow
continued processing of commands from initiators other than the initiator that
received the error.  Gene's proposal will include identification of the new
behavior via some additional usage of an existing mode page.

8.    Meeting Schedule

The next meeting of SCSI Working Group will be September 9-10, 1997, in
Nashua, NH at the Crowne Plaza Nashua Hotel (603-886-1200), hosted by
Unitrode.

9.    Adjournment

The meeting was adjourned at 5:00 p.m. on Wednesday July 16, 1997.


--
John Lohmeyer                 E-Mail: john.lohmeyer at symbios.com
Symbios Logic Inc.             Voice: 719-533-7560
4420 ArrowsWest Dr.              Fax: 719-533-7036
Colo Spgs, CO 80907-3444    SCSI BBS: 719-533-7950 300--28800 baud

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