IBM TotalStorage SAN Volume Controller, Installation Manual

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reason, for example if the hard disk drive in the node fails, it is possible to copy all
the software from another node connected to the same fibre channel fabric. This
process is known as node rescue.
Power failure
The SAN Volume Controller runs on battery power when main power is lost.
Figure 36 shows that the SAN Volume Controller is running on battery power
because main power has been lost. All I/O operations have stopped. The node is
saving cluster metadata and the node cache data to the internal disk drive. When
the progress bar reaches zero, the node will power off.
Note: When input power is restored to the uninterruptible power supply, the SAN
Volume Controller is turned on without the front panel power button being
pressed.
Powering off
The progress bar on the display shows the progress of the power-off operation.
Figure 37 shows that the power button has been pressed and the node is powering
off. Powering off may take several minutes.
The progress bar moves backward when the power is removed.
Restarting
The front panel indicates when the software on a node is restarting.
Figure 35. Node-rescue-request display
P o w e r F a i l u r e
Figure 36. Power failure display
P o w e r i n g O f f
Figure 37. Powering-off display
Chapter 4. Using the front panel display on the SAN Volume Controller
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