@Atilla: While it does exist, it's not exposed in Finder's GUI, so it's another kettle of fish unless you're ready to fire up Terminal (
defaults write com.apple.Finder AppleShowAllFiles true if Google is to be trusted).
I'd also highly recommend *NOT* to do that on *any* kind of *nix, even if you're an advanced user, but that's just me

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And when you're there, as @Derf figured out, you're better off just doing everything over the CLI

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And in case your system is very sneaky or you happen to have multiple Kobos plugged in at once, diskutil is your friend to figure out where they're mounted.