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Cake day: June 15th, 2023

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  • Other commenters have pointed out the problems with overloading of connectors and reduced efficiency because of the added resistance but there is another really important reason not to chain power strips: circuit breakers work best against short circuits when the resistance between the breaker and the short is fairly low (for instance less than 0.5Ω) so that the current will quickly go over the rated current of the breaker. If the resistance is a lot higher because you have too many extensions between the breaker and the fault, the time the breaker needs to react will go up. Counterintuitively this usually means more energy will be turned to heat by the fault.

    In extreme cases this can mean the difference between a broken power strip that you can just throw out and a burned down house.








  • check the GRUB_CMDLINE_LINUX key in /etc/default/grub it should contain the info about any subvolume. if it does not then there might be another grub config hook that is used by Fedora to add that info. If you want to be able to change subvol names without having to touch the grub config you might also want to switch to using subvolid instead of subvol keys on the kernel command line, because the id will stay the same after a rename (this could backfire though if you assign functions to certain names like “fallback” etc.).

    Edit: found the hook that adds the kernel command line option for btrfs subvolumes. in /etc/grub.d/10_linux there is this bit of code:

    case x"$GRUB_FS" in
        xbtrfs)
            rootsubvol="`make_system_path_relative_to_its_root /`"
            rootsubvol="${rootsubvol#/}"
            if [ "x${rootsubvol}" != x ]; then
                GRUB_CMDLINE_LINUX="rootflags=subvol=${rootsubvol} ${GRUB_CMDLINE_LINUX}"
            fi;;
        xzfs)
            [skipped for brevity]
            ;;
    esac
    

    so it seems it is always looking at the subvol name of the currently mounted root fs.