Question: how to reboot hmc from command line?
Answer: Ground work: Ip address or hostname of the HMC. hscroot password to access the HMC. ... 
Reboot the HMC using command line. Login to the hmc with hscroot access. hmcshutdown -t now -r --> To reboot the HMC.
Reboot the HMC using GUI mode. Login to the HMC GUI using hscroot user account. ... 
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