SPC-3 issue of direct interest to iSCSI implementations

wrstuden at wasabisystems.com wrstuden at wasabisystems.com
Thu May 29 14:40:43 PDT 2003

* From the T10 Reflector (t10 at t10.org), posted by:
* wrstuden at wasabisystems.com
On Wed, 28 May 2003, Ralph Weber wrote:

> An SPC-3 editing review held in preparation for a T10 Letter Ballot
> has uncovered some problems with the definition of iSCSI TransportID
> values.
> TransportIDs are used by Access Controls and Persistent Reservations
> as a way for one initiator port to specify an action affecting
> another initiator port.
> Upon further review, problems have been found in a previously approved
> proposal to use TransportIDs to identify initiators in the PERSISTENT
> RESERVE OUT when the SPEC_I_PT (Specify Initiator Ports) bit is set to
> one.
> In all cases, the changes required to resolve the problems are technical
> in nature and a proposal to effect them has been uploaded:
>   ftp://ftp.t10.org/t10/document.03/03-203r0.pdf
> The proposed changes have the potential to affect existing iSCSI
> implementations that support Access Controls or the PERSISTENT
> RESERVE OUT SPEC_I_PT function. So, review and comment by ips
> participants is encouraged. Please direct comments to the T10
> reflector (t10 at t10.org).

As I'm not on the t10 list, please forgive me if this topic has been
raised before.

The one comment I have on this proposal is that the initiator name does
not follow the format that the iSCSI spec gives for use in SCSI parameter
data. From section 3.4.2, page 41 of draft-20:

      The SCSI Port Name MUST be used in iSCSI. When used in SCSI
      parameter data, the SCSI port name MUST be encoded as:
            - The iSCSI Name in UTF-8 format, followed by
            - a comma separator (1 byte), followed by
            - the ASCII character 'i' (for SCSI Initiator Port) or
            the ASCII character 't' (for SCSI Target Port) (1 byte),
            followed by
            - a comma separator (1 byte), followed by
            - a text encoding as a hex-constant (see Section 5.1 Text
            Format) of the ISID (for SCSI initiator port) or the
            portal group tag (for SCSI target port) including the
            initial 0X or 0x and the terminating null (14 bytes).

Besides being more specific, this change uses the ',' character to help
delineate the end of the name. While 'i' is a valid character in the name,
',' is not.

Also, the text refers to the "ISCSI SESSION ID". I am not familiar with
that, but I gather it is a reference to the ISID. The ISID is the
"Initiator Session ID".

Other than the changes above, looks good.

Take care,


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