TASK SET FULL Definition(s) in FC-TAPE and SAM-2

Dave Peterson dap at nsg0.network.com
Tue Mar 16 12:35:37 PST 1999


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* Dave Peterson <dap at nsg0.network.com>
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Howdy All,

FC-TAPE currently states in clause 9.2 for TASK SET FULL:

- TASK SET FULL (if Tagged Queuing is used or ULP resources are
unavailable)

SAM-2r10 states in clause 5.2:

TASK SET FULL. This status shall be implemented if the logical unit
supports the creation
of tagged tasks (see 4.9). This status shall be returned when the
logical unit receives a
command and does not have enough resources to enter the associated task
in the task set.

SAM-2r10 states in clause 4.8:

A Task Set is composed of zero or more Untagged Tasks or a combination
of zero or more
Tagged Tasks and zero or more Untagged Tasks.

So it seems to me TASK SET FULL should be implemented regardless.

Another issue: what is the proper SCSI Status to return if:

a) the lun does not support tagged tasks, is processing a command
received from one Initiator (has no reservation active), has enough
resources to receive another command and enter it into the Task Set,
and receives another command from a different Initiator.

My preference would be a BUSY.

b) the lun does not support tagged tasks, is processing a command
received from one Initiator (has no reservation active), does not have
enough resources to receive another command and enter it into the
Task Set,  and receives another command from a different Initiator.

I would expect a TASK SET FULL.

Comments?

--
===================================================================
Dave Peterson                     phone : 612-391-1008
Principal Engineer
StorageTek Network Business Group email: dap at network.com



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Howdy All, FC-TAPE currently states in clause 9.2 for TASK SET FULL: - TASK SET FULL (if Tagged Queuing is used or ULP resources are unavailable) SAM-2r10 states in clause 5.2: TASK SET FULL. This status shall be implemented if the logical unit supports the creation 
of tagged tasks (see 4.9). This status shall be returned when the logical unit receives a 
command and does not have enough resources to enter the associated task in the task set. SAM-2r10 states in clause 4.8: A Task Set is composed of zero or more Untagged Tasks or a combination of zero or more 
Tagged Tasks and zero or more Untagged Tasks. So it seems to me TASK SET FULL should be implemented regardless. Another issue: what is the proper SCSI Status to return if: a) the lun does not support tagged tasks, is processing a command received from one Initiator (has no reservation active), has enough resources to receive another command and enter it into the Task Set, 
and receives another command from a different Initiator. My preference would be a BUSY. b) the lun does not support tagged tasks, is processing a command received from one Initiator (has no reservation active), does not have enough resources to receive another command and enter it into the 
Task Set,  and receives another command from a different Initiator. I would expect a TASK SET FULL. Comments? -- 
===================================================================
Dave Peterson                     phone : 612-391-1008
Principal Engineer 
StorageTek Network Business Group email: dap at network.com  

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