Gary,

The rules for checking are in the footnotes. For example in table 71 footnote j describes the rules for checking the Reference Tag:

If type 1 protection is enabled, the device server checks the logical block reference tag by comparing it to the lower 4 bytes of the LBA associated with the logical block. If type 2 protection or type 3 protection is enabled, the device server checks the logical block reference tag if it has knowledge of the contents of the LOGICAL BLOCK REFERENCE TAG field. If type 2 protection is enabled, then this knowledge may be acquired through the EXPECTED INITIAL LOGICAL BLOCK REFERENCE TAG field in a WRITE (32) command (see 5.29). If type 3 protection is enabled, then the method for acquiring this knowledge is not defined by this standard.

That footnote is telling you that for type 3 protection the target only check the reference tag if the target knows what the content is be some means not defined by the standard.

Also, sending out a message on this reflector that states the information is "confidential information of Emulex Corporation" is a not a good way to get responses. In the future any such messages received on my machine will automatically be deleted.

Bye for now,
George Penokie

Dept 9A8 030-3 A410
E-Mail:    gop@us.ibm.com
Internal:  553-5208
External: 507-253-5208



Gary.Franco@Emulex.Com
Sent by: owner-t10@t10.org

11/25/2006 07:17 AM

To
<t10@t10.org>
cc
Subject
Type 3 protection





I would like a clarification on the correct implementation for Type 3 checking when dealing with WRPROTECT/RDPROTECT/VRPROTECT .

In SBC-3r07 clause 4.17.2.5 Type 3 protection states:

Type 3 protection:

a)      defines the content of the LOGICAL BLOCK GUARD field within the logical blocks of the data-in buffer and/or data-out buffer;

b)      does not define the content of the LOGICAL BLOCK APPLICATION TAG field; and

c)      does not define the content of the LOGICAL BLOCK REFERENCE TAG field.

However in the individual command descriptors, WRITE(10) for example, Table 71 — WRPROTECT field indicates that both the Application Tag and Reference Tag should be checked.

Since both of these DIF items are not defined for Type 3 protection, I assume that for Type 3 protected devices these fields should not be checked at all.

Can someone clarify?

Thanks in advance

__________________________________
Gary Franco Consultant Engineer
Emulex Network Systems
972-671-7433 Dallas Office
972-671-7435 Dallas Office Fax

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