LUICLR bit in Extended Inquiry Data

Gerry Houlder gerry.houlder at seagate.com
Thu Sep 9 08:03:46 PDT 2010


Formatted message: <a href="http://www.t10.org/cgi-bin/ac.pl?t=r&f=r1009090_f.htm">HTML-formatted message</a>

Thats a little better, but still seems a bit obtuse to me. How about:
A logical unit I_T nexus clear (LUICLR) bit set to one indicates the SCSI
target device, after reporting a unit attention condition with an additional
sense code of REPORTED LUNS DATA HAS CHANGED for any logical unit, shall
clear that unit attention condition for all logical units accessible to that
SCSI target device. An LUICLR bit set to zero indicates the SCSI target
device clears unit attention conditions according to a previous version of
this standard. The LUICLR bit shall be set to one.
On Fri, Sep 3, 2010 at 6:12 PM, Kevin D Butt <kdbutt at us.ibm.com> wrote:
> In SPC-4r26, Extended Inquiry Data VPD Page, I find the following bit
> description.
>
> <<A logical unit I_T nexus clear (LUICLR) bit set to one indicates the
> SCSI target device clears any unit attention
> condition with an additional sense code of REPORTED LUNS DATA HAS CHANGED
> in each logical unit accessible
> to an I_T nexus after reporting the unit attention condition for any
> logical unit over that I_T nexus (see
> SAM-4). An LUICLR bit set to zero indicates the SCSI target device clears
> unit attention conditions according to a
> previous version of this standard. The LUICLR bit shall be set to one.>>
>
> I read it several times and it did not make sense to me.  After a good bit
> of scrutiny, I determined that it must mean that if the REPORTED LUNS DATA
> HAS CHANGED UA is reported by LUN A over I_T nexus (2), then all LUNs
> accessible over I_T nexus (2) also clear the REPORTED LUNS DATA HAS
> CHANGED UA.  However, it is possible that I am misinterpreting this
> requirement.	If I have interpreted this correctly, wouldn't it be better
to
> say:
>
> A logical unit I_T nexus clear (LUICLR) bit set to one indicates the SCSI
> target device clears any unit attention condition with an additional sense
> code of REPORTED LUNS DATA HAS CHANGED in each logical unit accessible to
an
> I_T nexus after reporting the <<REPORTED LUNS DATA HAS CHANGED>> unit
> attention condition for any logical unit over that same I_T nexus (see
> SAM-4). An LUICLR bit set to zero indicates the SCSI target device clears
> unit attention conditions according to a previous version of this standard.
> The LUICLR bit shall be set to one.
>
> Thanks,
>
> Kevin D. Butt
> SCSI & Fibre Channel Architect, Tape Firmware
> MS 6TYA, 9000 S. Rita Rd., Tucson, AZ 85744
> Tel: 520-799-5280
> Fax: 520-799-2723 (T/L:321)
> Email address: kdbutt at us.ibm.com
> http://www-03.ibm.com/servers/storage/



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