SES document: review, document availability, and changes to create Rev 5.0

Bob Snively Bob.Snively at Eng.Sun.COM
Wed Jun 5 09:47:34 PDT 1996


* From the SCSI Reflector, posted by:
* Bob.Snively at Eng.Sun.COM (Bob Snively)
*



Memo to:		Distribution

Memo From:		Bob Snively (bob.snively at sun.com)

Subject:		Changes to SES document,  and editorial meeting


A)	MEETING


An editorial review meeting and conference call is now scheduled for
Monday, June 24, 1996 at Sun Microsystems in Menlo Park, CA to review
revision 5.0 of the SES document.  The conference call details will be
announced later.

Please mark-up and fax any trivial editorial changes to me, leaving
me a phone message so that I will go look in the FAX stack for your
inputs.  FAX #	415-786-7816.  Phone #  415-786-6694.  That will leave
just technical inputs for the review meeting.

The meeting will be held at Sun's Menlo Park facility on the corner of
Willow Road and Bayfront Expressway in Menlo Park from 9 am to 5 pm.
Snacks will be available from 8:30.  Lunch will be provided.

For those who want to attend directly, many hotels are in the area.  
The two most convenient airports are San Jose and San Francisco.

For those who want to attend by telephone, be alert for the conference
call details that will be transmitted later on this same alias.


B)	DOCUMENT AVAILABILITY

The SES Revision 5.0 document will be available by anonymous ftp.

	Server:		playground.sun.com

	Directory:	/pub/ESI

	File names:	sesfpf.ps	(post-script, first page first)
			seslpf.ps	(post-script, last page first)

If you have never used anonymous ftp, the following tips may help:

	>       ftp  playground.sun.com

	Name (playground.sun.com:  ):  anonymous

	Guest login ok, send ident as password.

	Password:   your.name at your.company.com

	ftp>	cd pub/ESI

	ftp>	ls -l

		PORT command successful.
		ASCII data connection for /bin/ls (192.9.9.1,2426) (0 bytes).
		total 2240
		-rw-r--r--   1 10768    10        560082 Jun  5 16:34 sesfpf.ps
		-rw-r--r--   1 10768    10        560083 Jun  5 16:35 seslpf.ps
		ASCII Transfer complete.

	ftp>    get sesfpf.ps  /your/directory/sesfpf.ps

		(gets file with lots of chit-chat)

	ftp>	quit

		Goodbye.


C)	OVERVIEW OF CHANGES TO DOCUMENT.


MAJOR TECHNICAL CHANGES

1)   Clause 5.1

	The present text indicates the number of bytes to be transferred
	by a SEND DIAGNOSTIC command when the allocation length is not valid.

		"The actual number of bytes transferred across 
		the SCSI connection shall be the allocation length or four, 
		whichever is shorter."

	This restriction is unnecessary and the text has been changed to
	read:

		"The actual number of bytes transferred across the
		SCSI connection shall be less than or equal to the 
		allocation length. The control information in the
		diagnostic parameter field of the page shall not be 
		used by the environmental services process."

2)	Installation of flat addressing

	5.1	Type descriptor header requires that SCSI device headers
		for the primary enclosure and all sub-enclosures come first.

		Table 5	Byte 1 is redefined as the sub-enclosure identifier.

		Descriptive text is provided.

	Normative Annex

		A new normative annex, Annex A, is written to describe
		the flat addressing mechanism.


TECHNICAL CHANGES OF SECONDARY IMPORTANCE

1)  Clause 3.1

	Added the following definitions to clause 3.1

	device	(from SAM)

	enclosure:
		

	enclosure services: 
		Those services provided by an enclosure of one or more SCSI 
		devices that establish the mechanical environment, electrical 
		environment, and external indicators and controls for the 
		proper operation and maintenance of the devices.

	enclosure services device: 
		A SCSI device that monitors and controls enclosure services.

	enclosure services process: 
		The object that manages and implements the enclosure services 
		and the device server for the enclosure services device.

	enclosure services processor: 
		The physical entity that implements the enclosure services 
		process.

	initiator (from SAM)

	logical unit (from SAM)

	SCSI device (from SAM)

	target (from SAM) 

2)  Clause 5.1.1

	The use of a number of possible elements value of zero is described.

3)  Clause 5.1.1

	The type descriptor headers for device elements are clearly defined 
	as coming first in the configuration list.

4)  Clause 5.1.2

	See issues and questions item 4.  The error conditions for
	enclosure control pages are specified, including setting the 
	invalid operation requested (see 4 above).

5)  Clause 5.1.3, 5.1.10

	See issues and questions item 4.  The error bit for
	invalid operation attempted (particularly invalid string
	out contents) is specified for byte 1 of the ES enclosure
	status page and the ES array status page.

6)  Clause 5.1.5

	See issues and questions item 4.  The error conditions for
	string out pages are specified, including setting the 
	invalid operation requested (see 4 above), are established. 

7)  Clause 5.1.7

	See issues and questions item 4.  The error conditions for
	threshold out pages are specified, including setting the 
	invalid operation requested (see 4 above), are established.


8)  Clause 5.1.7

	The threshold values were previously defined as constrained to
	the same format as the values presented in the element entries. 
	The text has been modified to indicate that the threshold values
	are defined in the element entry text, but that the threshold
	value may be specified in a different format.  This is required
	when 16-bit or negative sensor values are defined, particularly
	the voltage and current sensors defined by Clauses 6.2.18
	and 6.2.19.

9)   Clause 5.1.9

	The text is clarified to show that only device element entries are
	included in the array control page and that all other elements
	are not provided.

10)  Clause 5.1.9

	See issues and questions item 4.  The error conditions for
	array control pages are specified, including setting the 
	invalid operation requested (see 4 above), are established.

11)  Clause 5.1.10

	The text is clarified to show that only device element entries are
	included in the array status page and that all other elements
	are not provided.

12)  Clause 5.1.12

	An enclosure presenting short status may have unpredictable
	behavior if one of the control commands (string out, enclosure
	control, array control, or threshold out) are transmitted to it.

	This is clarified in the text on short status.  Mandatory behavior
	is the transmission of a CHECK CONDITION with an ASC/ASCQ indicating 
	that the Unspecified Enclosure Services Failure or Unsupported 
	Enclosure Function.


13)  Generation Code

	The generation code is specified as having the same value as
	that specified for the configuration page in the other pages
	that include it.  This modifies the text in clauses 5.1.3, 
	5.1.10, and 5.1.11.

14)  Clause 6.1.1 and all element definitions.

	The disable bit was originally defined for sensors only.  The
	definition is extended to all elements. The interpretation for
	each element is individually described.

15)  All element definitions.

	Text is placed in the document to reference the tables.

16)  All element definitions except device elements.

	Table titles and other titles are modified to indicate that
	these are only defined for enclosure control and enclosure status pages.

17)  Clarify definition of temperature sensor element.

	The text is modified to describe the behavior of the element with
	respect to the threshold values.  Clause 6.2.6

18)  Define Select/Report bits for ES controller electronics

	The Select and Report functions are defined to select which
	ES controller electronics element should be the master of the enclosure 
	and to report which ES controller electronics element is actually
	the master of the enclosure.  Clause 6.2.9

19)  Define Report bits for SCC controller electronics and SCSI Target Port

	The Report functions are defined to report which ES controller 
	electronics element is actually executing the SCSI command
	sequence and which port on the controller is passing the
	information.  This allows the SCC controller electronics to
	be related to a SCSI Target and LU address.  Note that
	this bit is not necessary for the SCSI Initiator Port or SCSI 
	port/transceiver.  The SCSI initiator port is uniquely identified by
	the hierarchical or fixed address structure.  The SCSI port/transceiver
	is uniquely identified by the SCSI Target Port.
	Clause 6.2.10 and 6.2.20.


20)  Clarify definition of UPS

	the text is modified to describe the behavior of the UPS battery
	status value with respect to the threshold values.  Clause 6.2.12

21)  Clarify definition of voltage and current sensors.

	The text is modified to describe the behavior of the voltage
	and current sensor values with respect to the threshold values.
	Clause 6.2.18 and 6.2.19.  Note the issue concerning the
	resolution of the threshold values for voltage and current
	sensors.

22)  ESS bit renamed

	Annex B (formerly Annex A) now defines the ESS bit by the name
	EncServ bit.

23)  PF bit renamed and moved

	Annex B (formerly Annex A) now defines the PF bit as the PCV
	bit and moves it to bit 0 of the byte.


EDITORIAL CHANGES:

	Numerous grammatical corrections, all clauses.

	Numerous corrections of table formats, all clauses.

	Restructured clause 3 to provide a separate clause for
	the keywords:  expected, mandatory, may, optional, reserved, shall,
	should

	Removed proscribed words, including "will", "can", "may not", 
	"set to 1", "set to 0", "might", and others, rewriting the sentences
	as required.

	Restructured clause 3 to provide a separate editorial conventions from
	keyword description.

	Clause 5.1.2, word-smithing of Non-Crit and Crit bit definitions

	Clause 5.1.7, word-smithing of enclosure failure and enclosure
	degraded warnings for straying outside the specified thresholds.

	Clause 5.1.9, 1st paragraph:  clean up awkward structure

	Clause 5.1.10, 2nd paragraph:  clean up awkward structure

	Clause 5.1.12, note is moved to foot note.

	The words "simple devices" are replaced with the words
	"simple enclosure processors" where they are found.

ISSUES AND QUESTIONS:

1)	Note that the voltage and current values specified for voltage
	sensors and current sensors require a specialized mapping to the
	threshold values.  The threshold values only can be set in 256 ma
	256 mv increments.

	To make this work properly, the threshold values must be modified
	to be specified as having the same format as specified in the
	the element entry text, which may not be such a simple
	relationship as that previously specified in clause 5.1.7.

2)	The sub-enclosure addressing structure extends the help text
	page by inserting a sub-enclosure header at the beginning of
	each help string.  This allows the string to be associated with
	the proper sub-enclosure.

	At present, the header is not provided for SES devices not
	using the sub-enclosure addressing structure.  Should the
	page be modified so that a single enclosure implementation
	has the same format?

	The same question applies to the ES String Out and ES String In
	pages.

3)	The present definition of the sub-enclosure addressing structure
	for the ES String Out page allows only a single sub-enclosure
	to receive information at one time.  This is not symmetric with
	the string in page, but eliminates the requirement for installing
	control bits that prevent the sending of strings to sub-enclosures
	that should not be updated at the time another sub-enclosure must
	receive a string.

4)	Invalid strings sent out to an enclosure would normally be
	expected to cause a CHECK CONDITION to be presented, indicating
	invalid information in the data field.  However, any non-SES
	device with a ES process running behind it (i.e., with the
	EncServ bit set in the Inquiry field) would not be able to 
	present a CHECK CONDITION.  The information must be presented
	in one of the ES status pages.  A new bit (InvOp) is assigned in 
	byte 1 of the ES enclosure status page and the ES array status page to
	indicate once only that an invalid operation was attempted to
	the enclosure and was subsequently ignored by the enclosure.

	The same problem is also present for the threshold out page,
	the enclosure control page, and the array control page and the
	same solution will be used.

	The InvOp bit is not presently defined as settable by the
	application client in the array control and enclosure control pages.

5)	Enclosures presenting short status are not allowed to be
	sub-enclosures.  Such enclosures are treated as elements with
	the new type of "simple sub-enclosure".

6)	An enclosure presenting short status may have unpredictable
	behavior if one of the control commands (string out, enclosure
	control, array control, or threshold out) are transmitted to it.

	This is clarified in the text on short status.  Mandatory behavior
	is the transmission of a CHECK CONDITION with an ASC/ASCQ indicating 
	that the Unspecified Enclosure Services Failure or Unsupported 
	Enclosure Function.  This should work fine for SFF devices and
	other devices that service the ES processor indirectly.

7)	The 8-byte world wide name is specified as an FC-PH value.
	This may require some additions to either SPC or SAM-2 to
	make sure that everyone knows how to make these values
	unique.

	As a generic problem, the WWN must be settable for volume
	sets.  This is not a problem for SES devices, since all the
	components that expose a WWN are by definition physical devices.





More information about the T10 mailing list