Ups Operation; Ups - IBM 2145-8F4 Installation Manual

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UPS operation

The following table provides the UPS guidelines for the SAN Volume Controller
2145-8F2 and the SAN Volume Controller 2145-8F4:
Number of SAN Volume
Controller 2145-8F2 or SAN
Volume Controller 2145-8F4
models
2
4
6
8
Attention:
1. Do not connect the UPSs to an input power source that does not
conform to standards.
2. Each UPS pair must power only one SAN Volume Controller cluster.
Each UPS includes power (line) cords that connect the UPS to either a rack power
distribution unit (PDU), if one exists, or to an external power source.
The UPS is connected to the SAN Volume Controller nodes with a power cable and
a signal cable. To avoid the possibility of power and signal cables being connected
to different UPS units, these cables are wrapped together and supplied as a single
field replaceable unit. The signal cables enable the SAN Volume Controller nodes
to read status and identification information from the UPS.
Each SAN Volume Controller node monitors the operational state of the
uninterruptible power supply (UPS) to which it is attached.
If the UPS reports a loss of input power, the SAN Volume Controller node stops all
I/O operations and dumps the contents of its dynamic random access memory
(DRAM) to the internal disk drive. When input power to the UPS is restored, the
SAN Volume Controller node restarts and restores the original contents of the
DRAM from the data saved on the disk drive.
A SAN Volume Controller node is not fully operational until the UPS battery
charge state indicates that it has sufficient capacity to power the SAN Volume
Controller node long enough to save all of its memory to the disk drive. This is in
the event of a power loss. The UPS has sufficient capacity to save all the data on
the SAN Volume Controller node at least twice. For a fully-charged UPS, even after
battery capacity has been used to power the SAN Volume Controller node while it
saves DRAM data, sufficient battery capacity remains to allow the SAN Volume
Controller node to become fully operational as soon as input power is restored.
Note: If input power is disconnected from the UPS, a fully-operational SAN
Volume Controller node that is connected to that UPS performs a
power-down sequence. This operation, which saves the configuration and
cache data to an internal disk in the SAN Volume Controller node, typically
takes about three minutes, at which time power is removed from the output
of the UPS. In the event of a delay in the completion of the power-down
sequence, the UPS output power is removed five minutes after the power is
disconnected from the UPS. Because this operation is controlled by the SAN
Number of 2145 UPS units
Not supported
Not supported
Not supported
Not supported
Number of 2145 UPS-1U
units
2
4
6
8
Chapter 2. UPS
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