Chapter 5. Replacing The Real-Time Clock Battery - Lenovo ThinkSystem DM240N Service Manual

Chapter 5. Replacing the real-time clock battery

You can replace a failed real-time clock (RTC) battery nondisruptively in an DM240N drive shelf that is
powered on, and while I/O is in progress.
Before you begin
• All other components in the system must be functioning properly.
• You must have verified that the shelf containing the failed FRU is cabled correctly, by downloading and
running ThinkSystem Intelligent Monitoring Config Advisor. If any cabling errors are generated, follow the
corrective actions provided.
Lenovo Downloads: ThinkSystem Intelligent Monitoring Config Advisor
About this task
• Allow at least 70 seconds between removal and installation of the NVMe shelf module (NSM).70 seconds
is the time it takes for ONTAP to recover: clean up the data structures and the driver to register the shelf ID
correctly.
• Best practice: The best practice is to have current versions of NVMe shelf module (NSM) firmware and
drive firmware on your system before replacing FRU components.
Note: Do not revert firmware to a version that does not support your shelf and its components.
Lenovo Downloads: Disk Shelf Firmware
Lenovo Downloads: Disk Drive and Firmware
• If needed, you can turn on the shelf's location (blue) LEDs to aid in physically locating the affected shelf:
storage shelf location-led modify -shelf-name shelf_name -led-status on If you do not know the shelf_
name of the affected shelf, run the storage shelf show command.
A shelf has three location LEDs: one on the operator display panel and one on each NSM module.
Location LEDs remain illuminated for 30 minutes. You can turn them off by entering the same command,
but using the off option.
• When you unpack the replacement RTC battery, save all packing materials for use when you return the
failed RTC battery. You return the failed part to Lenovo as described in the RMA instructions shipped with
the kit. If you need the RMA number or additional help with the replacement procedure, contact technical
support at Lenovo Support
800 (Asia/Pacific).
A video for this task is available at:
• Youtube: https://www.youtube.com/playlist?list=PLYV5R7hVcs-BhZmHgn868u8QatfgH8JW4
• Youku: https://list.youku.com/albumlist/show/id_52419127
Step 1. Properly ground yourself.
Step 2. Disconnect the cabling from the NSM module that contains the FRU that you are replacing:
a. Disconnect the power cord from the power supply by opening the power cord retainer, and
then unplug the power cord from the power supply. Power supplies do not have a power
switch.
b. Disconnect the storage cabling from the NSM module ports. Make a note of the NSM module
ports that each cable is connected to. You reconnect the cables to the same ports when you
reinsert the NSM module, later in this procedure.
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