1.2 Status Byte
(2)CHECK CONDITION status
This status is reported in the following cases a) to c). The IDD generates sense data when it reports this status and indicates the detailed cause. The INIT issues a REQUEST SENSE command when it receives this status and should sample sense data.
a)If the sense key of the sense data indicates RECOVERED ERROR [=1], the last command, which is the last command, indicates that it ended normally with the error recovery processing executed by the IDD.
b)If the sense key of the sense data indicates UNIT ATTENTION [=6], it indicates that the IDD was holding the UNIT ATTENTION condition. Details of the UNIT ATTENTION condition are described in Section 1.5.
c)In cases other than the above, it indicates that command execution is impossible, or that command execution was terminated abnormally.
(3)CONDITION MET Status
This status is reported when it is possible to secure the cache memory area necessary for reading all the logical data blocks specified in the
The IDD does not support the
(4)BUSY status
This status indicates that the IDD is in the busy state and it cannot receive a new command. Normally, an INIT that receives this status reissues the original command after waiting an appropriate period of time.
The IDD reports the BUSY status in the following cases (the command stack function is explained in Section 1.4).
a)If the IDD receives a new command while it is executing or is queuing command (except a command without executing disconnect processing as shown in Section 1.3.3) but the INIT which issued that command does not satisfy the disconnect enable conditions.
b)If the IDD receives a command without executing disconnect processing (as shown in Section 1.3.3) while it is executing or is queuing command.
c)If the DISCONNECT message for command queuing has been rejected by the INIT while the IDD is executing or queuing command.
d)If a command with executing untagged disconnect processing is received while the command queue is full.
(5)INTERMEDIATE status
This status indicates that a command which specifies a link (except the last command in a group of linked commands with “1” as its Link bit) has been completed normally. If a command which specifies a link is completed abnormally and the CHECK CONDITION status or RESERVATION CONFLICT status is reported, the command link is broken an the subsequent linked commands are not executed.
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