
2-12
SCSI REFERENCE 1014826
CHAPTER 2—OVERVIEW OF THE LIBRARY AS A SCSI DEVICE
Status Descriptions
The following are expanded descriptions of the status bytes listed in Ta b l e 2 - 2 .
Good The library returns Good status to indicate that the operation specified
by the CDB completed normally.
Check Condition The library returns Check Condition status to indicate that
an error has occurred while it was executing a command. The library reports
Check Condition status as soon as it detects the error unless it is disconnected
from the SCSI bus. If the library is disconnected, it reports Check Condition
status after the reconnect process.
Examples of situations that result in Check Condition status are listed below:
You send an Identify message with an invalid LUN followed by a command
other than INQUIRY or REQUEST SENSE.
You send a command other than INQUIRY or REQUEST SENSE when there
is a pending Unit Attention condition of the library.
The library has an unrecoverable hardware error and receives a motion
command.
The library is not ready when it receives a motion command.
You set a reserved field to a value other than 0 in the CDB or the parameter
list for the requested command.
You specify an invalid parameter in the CDB or parameter list for the
requested command.
The command fails for one of the reasons listed in the command chapter. For
example, a MOVE MEDIUM command terminates with Check Condition
status if the source for the move is empty.
For specific situations that return Check Condition status, refer to the
command descriptions in Chapter 4 through Chapter 25.
Busy Indicates that the library is temporarily unable to accept a command
from this initiator. The initiator may retry the command later.
Reservation Conflict The library returns Reservation Conflict status to
indicate that the library is currently reserved by another initiator. This status is
reported until the initiator that reserved the library issues a RELEASE (17h or
57h) command or a reset condition occurs.
2.2.4 COMMAND FORMAT ERRORS
A command format error may occur when:
The Operation Code in the CDB is not supported by the library.
Comentarios a estos manuales