98-115r1 - Sundry Minor Enhancements for SPC-2
ROWEBER at acm.org
ROWEBER at acm.org
Tue Feb 10 15:25:42 PST 1998
* From the T10 (formerly SCSI) Reflector (t10 at symbios.com), posted by:
* ROWEBER at acm.org
Date: 10 February, 1998
To: T10 Membership
From: Ralph Weber, T10 Alternate member from Symbios, Inc.
Subject: Sundry Minor Enhancements for SPC-2
During the past several months various suggestions have been made for minor
enhancements in SPC-2. These proposals are complied here for consideration
1) Add the following before the last sentence in clause 4.2.4:
"If the information being transferred to the data-in buffer includes fields
containing counts of the number of bytes in some or all of the data, the
contents of these fields shall not be altered to reflect the truncation,
if any, that results from an insufficient allocation length value, unless
the standard that describes the data-in buffer format specifically states
It has been noted that most command descriptions include wording with effects
similar to what is proposed above. However, some command descriptions are
silent on this subject and adding the proposed wording in clause 4.2.4 (the
description of the allocation length CDB field) will cover all cases.
2) In the process of resolving an issue regarding field pointer bytes sense-key
specific data in the standard sense data (see 97-187), the working group
produced the following statement of its position regarding multi-byte fields:
a) A multi-byte field is a defined field in a CDB or parameter list whose
length exceeds one byte; and
b) The contents of the sense-key specific data for the ILLEGAL REQUEST sense
key is not specified by SCSI-2 when the error occurs in a reserved field.
The following should be added at the end of the third paragraph after Table 63
in clause 7.20.1 to embody the committee's position in SPC-2:
"If a field whose length exceeds one byte is reserved, it shall be treated
as a multiple-byte field. If several consecutive bytes are individually
reserved, each shall be treated as a single-byte field."
3) It has been noted that no SCSI standard contains the requirement that
invalid operation codes result in a CHECK CONDITION status. To address this
omission, the following wording should be added at the end of the second
paragraph in clause 4.2:
"If a device server receives a CDB containing an operation code that is
invalid or not supported, it shall return CHECK CONDITION status with the
sense key set to ILLEGAL REQUEST and an additional sense code of INVALID
COMMAND OPERATION CODE."
4) The SPC recommendations for virtual units regarding the contents of the
device identification VPD page have been overtaken by events, specifically the
IEEE Tutorial for SCSI use of IEEE company_id (also available as T10/97-101r2).
Unless or until an IEEE document number than can be referenced from an ANSI
standard becomes known to T10, note 53 (the first note in clause 8.4.3) should
be removed from SPC-2.
5) The description of the Identification descriptor field in the device
identification VPD page has been rendered incorrect by the addition of the
Association field. The second paragraph before Table 112 in clause 8.4.3
should be replaced with:
"Each Identification descriptor (see table 111) contains information
identifying the logical unit, physical device, or access path used by
the command and returned parameter data. The Association field indicates
the entity that the Identification descriptor describes. If a physical
or logical device returns an Identification descriptor with the
Association field set to 0h, it shall return the same descriptor when
it is accessed through any other path."
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