Proper status for Test Unit Ready Command when in drive is in Idle C or Standby.

Kevin_Marks at Dell.com Kevin_Marks at Dell.com
Mon Mar 16 14:05:46 PDT 2015


Formatted message: <a href="http://www.t10.org/cgi-bin/ac.pl?t=r&f=r1503162_f.htm">HTML-formatted message</a>

Ed,

I do not see where you get a CC for a TUR in Active_wait coming from Idle_c
in any of the state machines regardless of the CCF_IDLE. But agree with
Gerry, that the intent was to complete TUR with GOOD except in stopped or
wait states from stopped.

Kevin

From: owner-t10 at t10.org [mailto:owner-t10 at t10.org] On Behalf Of Gerry Houlder

Sent: Monday, March 16, 2015 8:36 AM

To: Edward Younk

Cc: t10 at t10.org

Subject: Re: Proper status for Test Unit Ready Command when in drive is in
Idle C or Standby.

Test Unit Ready response while in Idle_c should be GOOD status and drive
remains in Idle_c condition. T10 defined it this way so that an initiator
that occassionally polls with TUR would allow a drive to stay in idle or
standby condition.

On Fri, Mar 13, 2015 at 1:53 PM, Edward Younk
<Edward.Younk at hgst.com> wrote:

Hi Guys,

I have a question on the proper response to a test unit ready when the drive
is in idle-c, or one of the standby states, and the CCF fields in Mode page
0x1A are set to enable check condition on recovery, i.e. “10b”.

For example, assume the following command sequence.

Drive initially in Idle_C

Command 							  Status     
									     
	       Power State

Test Unit Ready 					       ???	     
									     
	       Drive remains in Idle-C

Read Command						    Ck Con Not_ready,
in process of becoming ready		 Drive goes to Active-Wait

Test Unit Ready 					       Ck Con
Not_ready, in process of becoming ready 	    Drive still in
Active-Wait

…..drive recovers to Active						     
									     
	  Drive in Active

Test Unit Ready 					       Good Status   
									     
     Drive in Active.

In this case, what should the first Test Unit Ready command return?  If it is
Good Status, isn’t it kind of strange that the first media access command
would then return that we are “Not Ready in Process of becoming Ready”. 
If it is a check condition, what is the Addition Key Code/Qual,  “Not
Ready, Cause not Reportable”.  It seems to me their should be a “Not
Ready, In Power Save State” Code/Qual

If the CCF Idle field is set to “01b” then the I think the sequence is
well understood.

Drive initially in Idle_C

Command 							  Status     
									     
	       Power State

Test Unit Ready 					      Good status    
									     
    Drive remains in Idle-C

Read Command						    Queue Command    
								       Drive
goes to Active-Wait

…..drive recovers to Active						     
									     
	  Drive in Active

Dequeue Read and Execute			Good Status		     
								    Drive in
Active

Test Unit Ready 					       Good Status   
									     
     Drive in Active.

Thanks,

Ed,




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