SAM-5 definition of physical reconfiguration

Ericson, George george.ericson at
Tue Jan 6 14:36:30 PST 2015

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The simple fix is to remove the word “physical” from the referenced
sentence.   Reconfiguration of “virtual” SCSI target devices has been the
practice for a very long time.	I expect an INQUIRY DATA HAS CHANGED event.


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

Sent: Tuesday, January 06, 2015 4:52 PM

To: T10 Reflector

Subject: Re: SAM-5 definition of physical reconfiguration

i tend to think of physical reconfiguration as a hardware change thing.
Changing cables around, moving a card from one slot to another, flicking a
switch. Things that are outside the scope of SCSI standards. i would consider
things that can be done with SCSI commands (e.g., MODE SELECT) to be more of
a logical reconfiguration that should't change a port identifier.

I will concede that we are now defining SCSI commands that can create or
remove logical units. This allows commands to create a virtual logical unit
in one location, tear it down, and recreate the same numbered logical unit in
another location within the same domain and have the same result as swapping
some cables or moving a PC card from one backpanel slot to another. This
muddies things a bit.

On Tue, Jan 6, 2015 at 3:10 PM, Kevin D Butt
<kdbutt at> wrote:

In of SAM-5r18 there is the following sentence.

The relative port identifier for a SCSI port shall not change once assigned
unless physical reconfiguration of the SCSI target device occurs.

What is the definition of "physical reconfiguration"?

Within my company I have opinions that oppose each other.

 1) physically change cables that are connected

 2) change the configuration settings (e.g., mode select)


Kevin D. Butt

SCSI Architect, Tape Firmware, T10 Standards

Data Protection & Retention

MS 6TYA, 9000 S. Rita Rd., Tucson, AZ 85744

Tel: 520-799-5280<tel:520-799-5280>

Fax: 520-799-2723<tel:520-799-2723> (T/L:321)

Email address: kdbutt at

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