Kevin,
Not specifically, but there is nothing that states
modifying user data shall not or should not cause a POR either but would not be
a good implemtation either. ;-)
Bye for now,
George
Penokie
LSI Corporation
3033 41st St. NW
Suite 100
Rochester, MN 55901
507-328-9017
george.penokie@lsi.com
George,
Thanks. Is there anything anywhere that states that
modifying a mode parameter shall not or should not cause a POR?
Kevin D. Butt
SCSI & Fibre Channel Architect,
Tape Firmware
MS 6TYA, 9000 S. Rita Rd., Tucson, AZ 85744
Tel:
520-799-2869 / 520-799-5280
Fax: 520-799-2723 (T/L:321)
Email address:
kdbutt@us.ibm.com
http://www-03.ibm.com/servers/storage/
| "Penokie, George"
<George.Penokie@lsi.com>
08/06/2008 01:54 PM
|
|
To
| Kevin D Butt/Tucson/IBM@IBMUS,
"t10@t10.org" <t10@t10.org>
|
|
cc
|
|
|
Subject
| RE: Mode Parameter changes and when
they take effect |
|
Kevin,
There are some ways that an action requested in
a command may be deferred. Those are:
1) when the command supports the IMMED
bit (MODE SENSE and MODE SELECT do not)
2) if the command has explicit rules defined as to when a
specific action is to take place ( Mode parameter block descriptor in the mode page parameters is an
example of that)
3) if a
specific page has explicit rules defined as to when a specific value is to take
affect. (I know of none but I did not do an extensive search)
If the mode
parameters you are referring to in your note do not have explicit rules stating
that are not required to take effect until a POR occurs then SAM requires them
to be valid on completion of the MODE SELECT command. In other words there is
nothing special about the MODE SELECT command that allows an implementation to
treat mode pages any different that any other kind of parameter data.
Bye for
now,
George Penokie
LSI Corporation
3033 41st St. NW
Suite 100
Rochester, MN
55901
507-328-9017
george.penokie@lsi.com
From: owner-t10@t10.org
[mailto:owner-t10@t10.org] On Behalf Of Kevin D Butt
Sent:
Wednesday, August 06, 2008 2:09 PM
To: t10@t10.org
Subject:
Mode Parameter changes and when they take effect
I have a question related
to Mode Parameters. I have searched SPC-4 (and earlier SPC versions) and
cannot find guidance about when the changes to mode parameters take effect.
This concern is related to configuration settings and differences in
expectations of various vendors.
Vendor 1 claims that any change to a mode parameter
shall become effective immediately and should not cause a device to
reboot.
Vendor 2
claims that changes to some mode parameters require a reboot before they can be
accomplished. As such the device automatically performs a POR on
completion of the Mode Select that changes one or more of these
parameters.
Vendor 3
also claims that changes to some mode parameters require a reboot before they
can be accomplished. This device,however, requires that an outside entity
send a command to force the device to perform a POR. The new values of the
mode parameters are not in effect until after the POR.
In another form of when do
parameters take effect, the requested change to the format (or density) does not
occur until a subsequent command (e.g., a Format, a Write from BOT,
etc.).
Is there
any guidance in SPC?
Thanks,
Kevin D. Butt
SCSI & Fibre Channel Architect, Tape
Firmware
MS 6TYA, 9000 S. Rita Rd., Tucson, AZ 85744
Tel: 520-799-2869 /
520-799-5280
Fax: 520-799-2723 (T/L:321)
Email address:
kdbutt@us.ibm.com
http://www-03.ibm.com/servers/storage/