Entendi. Você precisa executar como sudo
$ /opt/MegaRAID/storcli/storcli64 /c0 show all
Controller = 0
Status = Failure
Description = Controller 0 not found
$ sudo /opt/MegaRAID/storcli/storcli64 /c0 show all
Generating detailed summary of the adapter, it may take a while to complete.
Controller = 0
Status = Success
Description = None