FC-Tape minutes, Portsmouth, U.K., August 12, 1998
STEWART_R_WYATT at HP-Boise-om2.om.hp.com
STEWART_R_WYATT at HP-Boise-om2.om.hp.com
Tue Aug 18 09:34:40 PDT 1998
* From the T10 (formerly SCSI) Reflector (t10 at symbios.com), posted by:
* STEWART_R_WYATT at HP-Boise-om2.om.hp.com
FC-TAPE Meeting Minutes T1198-413.pdf
Portsmouth, U.K. 12 August 1998
1. Introductions: Facilitator, Dale LaFollette, STK, called the
meeting to order. This meeting was scheduled to run from 3 to 9 PM.
Dale had just discovered that the room would not be available after 5.
He proposed adjourning for supper at 5 and reconvening at 6:30 in a
different room. This was agreed to. The agenda was completed, but
because of the meeting breaks and the need to bring in outside
participants for specific items, the items were not completed in the
order listed in the agenda. To improve readability, these minutes are
organized into the agenda order.
As is customary, Dale had the participants introduce themselves.
2. Approval of this agenda: T11/98-374v0. Approved.
3. Approval of 7/14 Minutes: T11/98-363v0. Approved
4. Old Action Items:
Stewart Wyatt updated the minutes and posted them to the web site. He
also posted a TapeAlert announcement to the web site and the
reflector. Stephen Gold, HP, was in attendance at this meeting to make
a TapeAlert presentation. Dave Peterson is the new SSC editor. He has
received notes from Gary Stephens and Rob Basham. Dale LaFollette
extended the time for this meeting. Dale also posted a list of
commands to the reflector for review.
An additional action item was to obtain the location of the template
for making formal review comments: Stewart Wyatt contacted Rich
Taborek for this information after the tape meeting.
The location is:
(Locate the www.g2networks.com web site, select "Technology", then
"Fibre Channel", then "Comments on FC-AL-2 Rev 6.3", finally "Comment
5. Required SCSI Commands: T11/98-375v0
Dale LaFollette led a review of the SPC and SSC commands for inclusion
in FC-TAPE. Typically the required/prohibited status was determined by
vote. Some commands incurred some discussion which is included below.
Copy command - Brian Smith, Crossroads, said the copy command was
being implemented in some 3rd party devices. He expects that it may be
required in some tape drives in the future. Nevertheless the
participants roundly voted to prohibit it in this profile
There was also some discussion about eliminating six byte commands.
This was defeated since it would break many operating systems.
Dale also reviewed the SMC commands. Bob Snively noted that there are
other devices besides tapes that implement SMC commands and felt that
the decisions should be reviewed by a broader group. The group
concluded that this document would only apply to media changers for
FC-TAPES. Brian Smith, Crossroads, offered to sample other medium
changers requirements to to review and provide comments on this
6. ABTS proposal: Dave Baldwin, Emulex
Dave made two proposals. The first was to assign values to a new
parameter field in ABTS. The three assigned values are:
#1. Abort Exchange set bit 0 to 1
#2. Abort Sequence set bit 1 to 1
#3. Check Status set bit 2 to 1
The Check Status bit appeared to be redundant with REC. Dave was asked
to see if it added new capability to make it worth keeping.
Dave's second proposal was to allow the sequence recipient to be able
to abort the sequence as well as the sequence initiators. No one
7. FC-TAPE draft review. Editor Dave Peterson had completed REV 1.07
earlier this week.
Dave had four questions he wanted to discuss.
#1.SCSI Target Discovery ala FLA Clause 10.3 - Dave wanted some
guidance on how the target discovery process should be modified from
the PLDA to include public tapes. Jeff Stai, Brocade, was found and
invited to participate. Jeff said that he did not know what the
process should be but offered to consult with Dave in defining the
#2. FCP_CONF Issues - The original proposal was to use FCP_CONF in all
queued commands. Rob Basham (who was not present) is known to want to
use it only at certain checkpoints. Bob Snively was unhappy that a
process had not been defined to his satisfaction since the definition
left the target to request FCP_CONF at its discretion without
including an application model. Some discussion followed about the
necessity for the FCP_CONF. Dal Allan saw FCP_CONF as a check point
for error recovery. The point was made that the target only proceeds
when it has a successful transfer and so the FCP_CONF is unneeded.
Dave Peterson saw the need for FCP_CONF being with read operations
where the target is unaware of whether the host received the data. The
host may lose data internally because of an internal error and need to
have the data retransferred. He expects the target to keep the read
data in its buffer until the FCP_CONF is received.
Matthew Wakeley, HP, saw FCP_CONF as useful for queued read commands
to stop the drive when initiator detects a data error.
The discussion revealed some misunderstandings and enabled the group
to get a more consistent view of FCP_CONF. Bob Snively and Dave
Peterson will produce a model. A key point is that the FCP_CONF is not
to be sent on a read until all of the data is confirmed. Dal Allan
asked Dave Peterson to review the model with Rob Bashim. Dave will
post the completed model to the reflector.
#3. Public/Private Addressing - Dave Baldwin and Charles Binford noted
that the addressing options in the FLA precluded communication between
private initiators and public targets. Jim Coomes, Seagate, presented
his proposal, to correct this situation. Some discussion followed. It
was concluded that public devices should respond to either DD_AA&AL-PA
or 00_00&AL-PA. The target always returns frames with its public
address in the source ID. Some concern was expressed about whether
current implementations can support this requirement. The participants
were asked to review their implementations to see if this requirement
would break existing solutions. Several of the implementers were
uncertain how there applications work.
Brian Smith thought that private devices would ignore the area and
domain fields and argued hard to that effect. The remainder of the
participants felt that private addresses included the 00_00 in the
area and domain fields.
Jim Coomes's conclusion: All public devices reply to 0000 or DDAA in
the area and domain address fields at login. Dave Baldwin's extension:
Public device be allowed to interrogate every device with a private
address to allow for a consistent address approach during target
#4. Comments: Stewart Wyatt questioned support for all of the queuing
flavors. Some discussion followed but the group did not appear to want
to limit them.
Dave took the opportunity to review some more of Bob Snively's
comments posted before the previous meeting.
Bob wanted to prohibit half duplex operation - the group preferred
that the profile be silent on full and half duplex operation. Bob also
wanted to prohibit DHD - A long discussion followed between Bob, Dal
and Matthew about the relevance of specifying physical issues. Dave
supported Bob. Matthew doesn't want to write a new proposal when new
physical features are added to Fibre Channel. (MCM as an example.) Bob
felt that these things are necessary for interoperability. Dal pointed
out that support for these features can be learned in the login and
the profile can be silent on these issues without affecting
Discard policy. Voted for a redefined discard multiple policy. Single
is prohibited because it would allow the FCP_RSP to be sent up to the
upper level when there was missing read data.
ACA handling - required for queuing, prohibited otherwise.
Choice of class 3. Class 3 behavior is mandatory. Class 2 is optional,
all others are prohibited.
Continuously increasing sequence count - not supported in first
generation Seagate drives, allowed.
9. TapeAlert proposal: T11/98-373v0, Stephen Gold
TapeAlert presentation: T11/98-412v0 - The overheads Stephen used in
Stephen presented a brief over of TapeAlert. TapeAlert is a standard
method of presenting log data to backup software. It provides clear
message that can be presented to the user along with corrective action
recommendations. It can also be used in network applications. Examples
of reported errors include: cleaning requirements, worn out media,
wrong media. The TapeAlert messages are intended to be idiotic proof.
Stephen was asking for SSC support for using the reserved log page
0x2E. Dal Allan, ENDL, and Gary Stephens, FSI, responded noting that
Stephen should have gotten approval before hand. They thought he would
have to make a request to the T10 plenary for inclusion of the log
page in the SPC. Dale LaFollette checked the standard and found that
this log page was device specific and that the SSC could grant
permission to use it. The group agreed to make the assignment in the
next draft of the SSC. Dal told Stephen to post a comment to the SMC
to get it included in that document also.
The last item of discussion was whether to seek a letter ballot at the
T11.3 plenary the next morning. While the group has made considerable
progress, the majority feeling was that we are not ready. The best
schedule is to complete the profile by the September meeting and ask
the T11 (or T11.3) chair for a letter ballot before the October
There was some confusion about whether a letter ballot from T11.3 was
sufficient to go for public review or if T11 would also have to have a
letter ballot. Dal Allan was of the feeling that if T11 required a
letter ballot to skip the T11.3 letter ballot.
10. T10 New Business: None
11. T11 New Business: None
12. Review new action items: Stewart Wyatt
#1. Dave Baldwin, revise ABTS proposal, compare the ABTS Status Check
to the REC to see if any additional functionality is provided, obtain
a document number, post updated proposal to the reflector.
#2. Brian Smith, Crossroads, review media changer commands.
#3. Stewart Wyatt to post a copy of the TapeAlert presentation
#4. Dave Peterson to include TapeAlert in the next SSC draft which is
estimated to be completed by the November T10 meeting.
#4. Stephen Golding to post a comment to SMC for inclusion of
#5. Dave Peterson and Bob Snively will produce a model of FCP_CONF.
Dave will review it with Rob Bashim. Dave will post the model to the
#6. Relevant participants: Investigate capability of existing Fibre
Channel solutions to respond to both DDAA&ALPA and 0000&ALPA after
#7. Rich Toborek/Dal Allan is FC-TAPE what letter ballots are required
before the FC-TAPE proposal can go for public review.
13. Adjournment: 10 PM
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