UPS battery (U1 of B1 rack) was replaced.
We did it as hot swap. So there is no down time for any system.
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Ikeda-san found k1dc0 had console logs as follows.
Broadcast message from root@k1dc0 (Tue Jan 4 16:47:42 2022):
Emergency! Batteries have failed on UPS k1nds0. Change them NOW
We entered computer room and battery replacement was required (See Fig.1 and Fig.2)
Procedure is as follows.
1. Disconnect yellow plug from UPS body without any pre-process (See red circle in Fig.3)
2. Unscrew and remove battery (See cyan circle in Fig.3)
3. Insert new battery
4. Execute self-check (See Fig.4 and Fig.5)
