Discussion of 14-275r7

Gerry Houlder gerry.houlder at seagate.com
Wed Apr 1 09:23:31 PDT 2015


Formatted message: <a href="http://www.t10.org/cgi-bin/ac.pl?t=r&f=r1504014_f.htm">HTML-formatted message</a>

An additional concern about PI type 1 compatibility is the Application Tag
fields. The new 32 byte write command could use these fields with type 1 PI
if we construct suitable rules overriding the typical Type 1 defaults and
rules for interaction with the Application Tag mode page.
On Wed, Apr 1, 2015 at 10:25 AM, Gerry Houlder <gerry.houlder at seagate.com>
wrote:
> i am concerned that the interaction of this command with the various PI
> types is not well defined.
>
> The WRITE STREAM command includes all of the needed fields to work with PI
> type 2, but nothing is added to the Protection Information model clauses
> that indicate which protection types this is allowed for. The added fields
> would allow the command to be used with PI type 2 systems, but the
> equivalent WRITE (32) command is defined to not be allowed for PI types 0
> and 1. If you only intended this feature to work with PI type 2, then the
> STREAM_ID field could just have been added to the existing WRITE (32) --
> since you are creating a new command I presume you intend that it be used
> with at least PI type 0 as well. If you want to include PI type 1 also,
> then there should be some new rules that allow the storage device to ignore
> the EXPECTED INITIAL LOGICAL BLOCK REFERENCE TAG and use the LOGICAL BLOCK
> ADDRESS field (like PI type 1 does) instead for the expected initial
> logical block reference tag. The new rules should be added to the Protect
> Information Model clause (4.22) and probably includes some changes for all
> three PI type clauses to accommodate the new command.
>
>>
>



More information about the T10 mailing list