The Microsoft SCSI layer obviously supports Tagged Command Queuing. However,
what is not clear is whether the Microsoft iSCSI Initiator supports sending
those settings over the wire to an iSCSI target.

Does the implementation support ever sending commands with task attributes
other than "untagged" over the wire?

And if so, what SCSI INQUIRY or MODE PAGE data is required to elicit that
behavior from the Windows SCSI layer?

Tagged commands are controlled by the port and miniport driver. The port
driver determines when to use a tagged command but only if the miniport
supports this functionality.

Moojit
"mpoulos42" discussions.microsoft.com> wrote in message
news:C7202E83-36B8-41CA-8D43-40CC261BE368@microsoft.com...

Thanks, but still need some clarification. Is the iSCSI initiator a
"miniport" and does it support tagged commands?

"moojit" wrote:

"mpoulos42" discussions.microsoft.com> wrote in message
news:55D0C2FD-BC03-4598-B208-199D13628C74@microsoft.com...

If you're using MS Initiator as a software initiator (using a standard NIC
to talk to storage), then the MS iSCSI Initiator driver will generate tagged
commands if needed. If you're using MS Initiator on a system that has a
hardware HBA such as Qlogic's QLE4060, the STorport port driver and Qlogic
miniport driver will determine if tagged commands will be generated.

Moojit

Nonsense! For MS iSCSI initiator the only difference between "tagged
command queueing" enabled
or disabled is will it do serialization or not. If particular hard
disk drive reports it DOES support TGC
setting appropriate bit in it's SCSI inquiry data response then
initiator will NOT wait for command N
completion before sending command N+1 for execution. If device tells
it DOES NOT support TGC then
initiator WILL wait for command N to complete before sending command N
+1. Initiator does not generate
any commands itself, it simply receives full blown CDBs from upper
level driver in the stack (class driver
usually) and wraps CDBs into iSCSI PDUs.

Regards,
Anton Kolomyeytsev

CEO, Rocket Division Software

On Mar 15, 5:31 pm, "moojit" moojit.net> wrote:

"KOOLER" rocketdivision.com> wrote in message
news:f2bdb21a-b32e-4cd0-9976-25681a92c7cc@m3g2000hsc.googlegroups.com...
Nonsense! For MS iSCSI initiator the only difference between "tagged
command queueing" enabled
or disabled is will it do serialization or not. If particular hard
disk drive reports it DOES support TGC
setting appropriate bit in it's SCSI inquiry data response then
initiator will NOT wait for command N
completion before sending command N+1 for execution. If device tells
it DOES NOT support TGC then
initiator WILL wait for command N to complete before sending command N
+1. Initiator does not generate
any commands itself, it simply receives full blown CDBs from upper
level driver in the stack (class driver
usually) and wraps CDBs into iSCSI PDUs.

Regards,
Anton Kolomyeytsev

CEO, Rocket Division Software