Chapter four - tape cartridges – HP Integrity NonStop H-Series User Manual
Page 26

Chapter Four - Tape Cartridges
Tandem 5142-xSE Rackmount Tape Subsystems User Guide
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4.6
Unloading a Tape Cartridge
The cartridge ejects from the tape drive either when you press the Eject Button, or in response to a SCSI
LOAD/UNLOAD
command with the
LOAD
bit set to
0
.
Note:
If the drive is engaged in a task when you press the Eject button, it may be a long time before it
responds to the request, because it must first finish the task. This ensures that the task is terminated
in a controlled manner and no data is lost.
The drive rewinds, unloads and ejects the cartridge unless the drive is not in an idle state or a contingent
operation (which is locking the cartridge) with the host computer is active. The Tape LED slowly
flashes green while the tape unloads.
Note:
If the host has previously sent a
PREVENT MEDIA REMOVAL
command, the unloading action
is different in two ways:
1.
The Eject Button is disabled and has no effect when pushed. It does not initiate an unload
sequence.
2.
A
LOAD/UNLOAD
command with the LOAD bit set to zero takes the drive off-line and
unthreads the tape, but does not eject the cartridge.
The effects of
PREVENT MEDIA REMOVAL
continue until an
ALLOW MEDIA REMOVAL
command is received, or the drive is reset.
4.7
Forcing the Ejection of a Cartridge
Caution:
You may lose data if you force an eject. Also, the tape can end up invalidly formatted,
because End of Data (EOD) may not have been written. Because of this, only force ejection
as a last resort to recover a cartridge or if you are not prepared to wait for the normal eject
procedure and urgently need to unload the cartridge, even at the risk of losing data.
Press the Eject Button three times within a 5-minute period (or press the Eject Button twice within 5
minutes after a initiating a SCSI
UNLOAD
command). Hold the Eject Button down for at least 5 seconds.
Following either of these actions, the drive waits until 35 seconds have passed from the first time that the
Eject Button is pushed to give the normal eject procedure a chance to proceed. Once this period has
elapsed, the drive immediately unthreads the tape and ejects the cartridge, regardless of what operation it
was performing.. The drive is then reset as though the power has been switched off and then on again.
Note:
Forced ejection overrides any SCSI
PREVENT MEDIA REMOVAL
command that may be in
effect, and can abort any SCSI operations that may be in progress on the drive. If the host has
previously sent a
PREVENT MEDIA REMOVAL
command, the unloading action is different in
two ways:
1.
The Eject Button is disabled and has no effect when pushed. It does not initiate an unload
sequence.
2.
A
LOAD/UNLOAD
command with the LOAD bit set to zero takes the drive off-line and
unthreads the tape, but does not eject the cartridge.
The effects of
PREVENT MEDIA REMOVAL
continue until an
ALLOW MEDIA REMOVAL
command is received, or the drive is reset.