I would say, it means that current and saved are the same. You cannot change the saved page without changing the current operating mode, therefore you must always set the SP bit to 1, changing the current and saved page. A bit of zero would mean changing the saved page but not the current and this would not make sense if they were the same, hence the CC.

Kevin

From: owner-t10@t10.org [mailto:owner-t10@t10.org] On Behalf Of Eddy Quicksall
Sent: Wednesday, July 09, 2008 3:08 PM
To: t10@t10.org
Subject: Mode Sense

6.9 MODE SELECT(6) command

. . .

A save pages (SP) bit set to zero specifies that the device server shall perform the specified MODE SELECT
operation, and shall not save any mode pages. If the logical unit implements no distinction between current and
saved mode pages and the SP bit is set to zero, the command shall be terminated with CHECK CONDITION status,

. . .

If my target is not saving mode pages then I am assuming the "logical unit implements no distinction between current and saved mode pages". If that is the case then I don't understand the sentence because it would seem the initiator would have to set SP to 0; but 0 would cause a CHECK CONDITION. So I think I don't understand the meaning.

Can someone explain what this means?

Eddy