Hitachi 3080 G1, Hardware Reference Manual

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NVRAM backup battery pack
Each server contains a battery pack. The battery pack maintains the NVRAM
contents when the server is not receiving power (due to a power failure or a
short-term shut down). The battery pack is located behind the front bezel
cover of the server, on the left-hand side. The battery pack is hot-swappable
and can only be accessed after the front bezel has been removed.
Battery pack characteristics:
• Each server contains a single battery module. The module contains dual
redundancy inside.
• The battery pack uses NiMH technology.
• A battery pack has a two year operational life. A timer starts when a
server is booted for the first time, and the timer is manually restarted
when a replacement batter pack is installed. After two years of operation,
a log warning event is issued to warn the user that the battery pack should
be replaced.
• The battery pack is periodically tested to ensure it is operational.
• A fully charged battery pack maintains the NVRAM contents for
approximately 72 hours.
• When a new server is installed and powered on, the battery pack is not
fully charged (it will not be at 100% capacity). After being powered on, the
server performs tests and starts a conditioning cycle, which may take up
to 24 hours to complete. During the conditioning cycle, the full NVRAM
content backup protection time of 72 hours cannot be guaranteed.
• A replacement battery pack may not be fully charged (it may not be at
100% capacity) when it is installed. After a new battery pack is installed,
the server performs tests and starts a conditioning cycle, which may take
up to 24 hours. During the conditioning cycle, the full NVRAM content
backup protection time of 72 hours cannot be guaranteed.
• If a server is left powered off, the battery will discharge slowly. This means
that, when the server is powered up, the battery will take up to a certain
number of hours to reach full capacity and the time depends upon whether
a conditioning cycle is started. The scenarios are:
○
24 hours if a conditioning cycle is started
○
3 hours if a conditioning cycle is not started
During the time it takes for the battery pack to become fully charged, the
full 72 hours of NVRAM content protection cannot be guaranteed. The
actual amount of time that the NVRAM content is protected depends on
the charge level of the battery pack.
• A battery pack may become fully discharged because of improper
shutdown, a power outage that lasts longer than 72 hours, or if a server is
left unpowered for a long period of time.
If the battery pack is fully discharged:
36 Hitachi NAS Platform server components
Hitachi NAS Platform 3080 and 3090 G1 Hardware Reference