IBM IC35L036UWDY10 - Ultrastar 36.7 GB Hard Drive Specifications page 211

! the command is permitted to execute if the conditions to execute concurrently are met. (See
Section 11.5, "Concurrent I/O Process.")
! the command is added to the command queue for an I_T_L nexus under the following conditions:
- no Queue Tag message was received during the connection which established the I/O process,
- disconnection is allowed for the current I/O process
- there is no queued I/O process or active I/O process corresponding to the I_T_L nexus for the
current I/O process
- the command is not linked to a previous command
! the command is added to the command queue for an I_T_L_Q nexus under the following conditions:
- a Queue Tag message was received during the connection which established the I/O process
- Tagged Queuing is enabled (DQue, Mode Page A is set to zero)
- an I/O process (either active or queued) exists at the Target for this Initiator
- disconnection is allowed for the current I/O process
- there is no queued I/O process or active I/O process corresponding to the I_T_L_Q nexus for the
current I/O process
- the command is not linked to a previous command
! QUEUE FULL Status is returned under one of the following conditions:
- the command would otherwise be queued (according to the rules described above) but the com-
mand queue is full and all slots are utilized
- the command would otherwise be queued (according to the rules described above) but all of the
available command queue slots not reserved for use by another initiator are utilized
- Tagged Queuing is enabled (DQue is set to zero) and a FORMAT UNIT command was previously
queued but has not yet begun execution
- Tagged Queuing is enabled (DQue is set to zero) and a START STOP UNIT command was previ-
ously queued but has not yet begun execution
! BUSY Status is returned under one of the following conditions:
- Tagged Queuing is disabled (DQue = 1) and a FORMAT UNIT command was previously queued
but has not yet begun execution
- Tagged Queuing is disabled (DQue = 1) and a START STOP UNIT command was previously
queued but has not yet begun execution
- the command would otherwise be queued (according to the rules described above) but discon-
nection is not allowed for the current I/O process.
If a command is queued, command execution may still be prevented at a later time when the command
is dequeued to become an active I/O process. This occurs if command execution is prevented by another
internal Target condition listed in Section 11.1.1, "Priority of SCSI Status Byte Reporting" at the time the
command is dequeued.
Ultrastar 146Z10 hard disk drive specifications
195