Device Identification Proposal Rev 3 (95-240r3)

Lohmeyer, John JLOHMEYE at cosmpdaero.ftcollinsco.ncr.com
Mon Dec 4 14:32:00 PST 1995


Bob Snively suggested some improvements to revision 2 of my proposal on 
Device Identification which I have included in this document.  All of the 
changes occur before the first table.  If this ASCII version is not readable 
by the time it gets through your mailer, there is a Word 6 file on the SCSI 
BBS (95-240r3.doc) or I can email you a postscript file (224,954 bytes).

I have also received a suggestion that the code set field should be expanded 
to include Unicode (in addition to binary and ASCII).  I had not included 
Unicode (ISO 2-byte code set for representing non-Latin characters) because 
the IEEE identifers are binary and X3T10 IDs are ASCII.  Does anyone else 
think Unicode should be included?

John
 --
John Lohmeyer             E-Mail:  john.lohmeyer at symbios.com
Symbios Logic Inc.         Voice:  719-573-3362
1635 Aeroplaza Dr.           Fax:  719-573-3037
Colo Spgs, CO 80916     SCSI BBS:  719-574-0424 300--14400 baud

[[ 95-240R3.TXT : 4100 in 95-240R3.TXT ]]

                                                               X3T10/95-240 r3
          


     Date: December 4, 1995

       To: X3T10 Committee

     From: John Lohmeyer, Principal member from Symbios Logic

  Subject: Device Identification Page Proposal (Rev 3)


 At the July `95 SCSI working group meeting, I presented revision 0 of this
 proposal.  Rev 0 principally dealt with retrieving SCAM strings and defined an
 new mode select/sense page.  With the input I received at that meeting plus
 various discussions since the meeting, I have prepared revision 1.  This
 proposal would define a new Vital Product Data page and includes the ability
 to return multiple identifiers (e.g., a device may have both an X3T10
 identifier and an IEEE identifier).

 At the November `95 SCSI working group meeting, I received further input and
 have prepared revision 2 based on this input.  The concept of group
 identifiers was removed, several wording improvements were made, and an
 example was added.

|I received several comments on revision 2 from Bob Snively.  Revision 3
|incorporates his comments.

 Proposed changes to SPC are to replace the existing section 8.4.3 with the
 following paragraphs and to renumber the existing sections 8.4.3--8.4.5 to
 8.4.4--8.4.6, respectively.  All references to these sections would need to be
 adjusted, Table 93 would need to be updated, and subsequent tables would need
 to be renumbered.

|8.4.3 Device identification page

 The optional device identification page (see table xx) provides the means to
 retrieve zero or more identification descriptors for the logical unit.
|Logical units may have more than one identification descriptor (e.g., if both
|X3T10 and IEEE identifiers are supported).

|Device identifiers are intended to be assigned to the peripheral device (e.g.,
 a disk drive) and not to the currently mounted media in the case of removable
 media devices.  Media identification is outside the scope of this standard.
 It is expected that operating systems will make use of the device identifiers
 during system configuration activities to determine whether alternate paths
|exist for the same peripheral device.

|Device identifiers should not be assigned to logical units that do not
|directly map to a peripheral device (e.g., volume sets in the SCSI-3
|Controller Commands).  Such logical units should return a device
|identification page length of zero to indicate that there are no
|identification descriptors for the logical unit.

                     Table xx - Device identification page
 +=====-========-========-========-========-========-========-========-========+
 |  Bit|   7    |   6    |   5    |   4    |   3    |   2    |   1    |   0    |
 |Byte |        |        |        |        |        |        |        |        |
 |=====+==========================+============================================|
 | 0   | Peripheral qualifier     |           Peripheral device type           |
 |-----+-----------------------------------------------------------------------|
 | 1   |                           Page code (83h)                             |
 |-----+-----------------------------------------------------------------------|
 | 2   |                           Reserved                                    |
 |-----+-----------------------------------------------------------------------|
 | 3   |                           Page length (n-3)                           |
 |=====+=======================================================================|
 |     |                           Identification descriptor list              |
 |=====+=======================================================================|
 | 4   | (MSB)                                                                 |
 |- - -+- -                        Identification descriptor (0)            - -|
 |     |                                                                 (LSB) |
 |-----+-----------------------------------------------------------------------|
 |     |                           .                                           |
 |     |                           .                                           |
 |     |                           .                                           |
 |-----+-----------------------------------------------------------------------|
 |     | (MSB)                                                                 |
 |- - -+- -                        Identification descriptor (last)         - -|
 | n   |                                                                 (LSB) |
 +=============================================================================+

 Each Identification descriptor (see table xx+1) contains information
 identifying the logical unit.  If the logical unit is accessible through any
 other path, it shall return the same identification.


                     Table xx+1 - Identification descriptor
 +=====-========-========-========-========-========-========-========-========+
 |  Bit|   7    |   6    |   5    |   4    |   3    |   2    |   1    |   0    |
 |Byte |        |        |        |        |        |        |        |        |
 |=====+==========================+============================================|
 | 0   |        Reserved                   |         Code set                  |
 |-----+-----------------------------------------------------------------------|
 | 1   |        Reserved                   |         Identifier type           |
 |-----+-----------------------------------------------------------------------|
 | 2   |                           Reserved                                    |
 |-----+-----------------------------------------------------------------------|
 | 3   |                           Identifier length (m-3)                     |
 |-----+-----------------------------------------------------------------------|
 | 4   | (MSB)                                                                 |
 |- - -+- -                        Identifier                               - -|
 | m   |                                                                 (LSB) |
 +=============================================================================+


 The code set field specifies the code set used for the identifier field as
 described in table xx+2.  This field is intended to be an aid to software that
 displays the identifier field.

                              Table xx+2 - Code set
 +=======+=====================================================================+
 | Value | Description                                                         |
 +=======+=====================================================================+
 |   0   | Reserved                                                            |
 +-------+---------------------------------------------------------------------+
 |   1   | The identifier field contains binary values.                        |
 +-------+---------------------------------------------------------------------+
 |   2   | The identifier field only contains ASCII graphic codes (i.e., code  |
 |       | values 20h through 7Eh).                                            |
 +-------+---------------------------------------------------------------------+
 | 3-Fh  | Reserved                                                            |
 +=============================================================================+

 The identifier type field specifies the format and assignment authority for
 the identifier as described in table xx+3.

                          Table xx+3 - Identifier type
 +=======+=====================================================================+
 | Value | Description                                                         |
 +=======+=====================================================================+
 |   0   | No assignment authority was used and consequently the identifier    |
 |       | may not be globally unique (i.e., the identifier is vendor specific)|
 +-------+---------------------------------------------------------------------+
 |   1   | The first 8 bytes of the identifier field are an X3T10 Vendor ID    |
 |       | (see annex C).  The organization assigned to the X3T10 Vendor ID is |
 |       | responsible for ensuring that the remainder of the identifier field |
 |       | is unique.  One recommended method of constructing the remainder of |
 |       | the identifier field is to concatenate the product identification   |
 |       | field from the standard INQUIRY data field and the product serial   |
 |       | number field from the unit serial number page.                      |
 +-------+---------------------------------------------------------------------+
 |   2   | The identifier field contains an IEEE 64-bit identifier.  In this   |
 |       | case, the identifier length field shall be set to 8.  Note that the |
 |       | IEEE guidelines for 64-bit global identifiers specifies a method    |
 |       | for unambiguously encapsulating 48-bit identifiers as 64-bit        |
 |       | identifiers.                                                        |
 +-------+---------------------------------------------------------------------+
 |   3   | The identifier field contains an FC-PH 64-bit Name_Identifier field |
 |       | as defined in X3.230-1994.  In this case, the identifier length     |
 |       | shall be set to 8.                                                  |
 +-------+---------------------------------------------------------------------+
 | 4-Fh  | Reserved                                                            |
 +=============================================================================+

 The identifier length field specifies the length in bytes of the identifier.
 If the allocation length field of the command descriptor block is too small to
 transfer all of the identifier, the identifier length shall not be adjusted to
 reflect the truncation.

 The identifier field contains the identifier as described by the identifier
 type, code set, and identifier length fields.

 The following example is not a normative part of this standard.  The example
 assumes that the product is a direct-access device with an X3T10 Vendor ID of
 `XYZ_Corp', a product identification of  `Super Turbo Disk', and a product
 serial number of `2034589345'.  Furthermore, it is assumed that the
 manufacturer has been assigned a 24-bit IEEE company_id of 01ABCDh by the IEEE
 Registration Authority Committee and that the manufacture has assigned a 24-
 bit extension_identifier of 234567h to this logical unit.  The combined 48-bit
 identifier is reported in the 64-bit format as defined by the IEEE 64-bit
 Global Identifier (EUI-64) standard.  The data returned in the device
 identification VPD page for this logical unit would be:

                 Table xx+3 - Device identification page example
 +========-====================================================-================+
 | Bytes  | Hexadecimal Values                                 | ASCII Values   |
 +========+====================================================+================+
 | 00--15 | 00 83 00 32  02 01 00 22  58 59 5A 5F  43 6F 72 70 |...2..."XYZ_Corp|
 | 16--31 | 53 75 70 65  72 20 54 75  72 62 6F 20  44 69 73 6B |Super Turbo Disk|
 | 32--47 | 32 30 33 34  35 38 39 33  34 35 01 02  00 08 01 AB |2034589345......|
 | 48--53 | CD FF FF 23  45 67                                 |......          |
 +==============================================================================+

 Note: In the above table, non-printing ASCII characters are shown as `.'.






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