I'm currently trying to install Debian on a system with no video output. All I have is serial console.
I know how to get it started and all, and even made it install automatically with a preseeded config. The installation itself is absolutely no issue.

Now what I haven't figured out is how I can switch between the different tabs the installer has:


I'd love to have that so I can switch to the log and follow the installation in much more detail for debugging purposes (the installation itself runs fully automatically).

I already tried

  • Alt + 1-4
  • Alt + F1-F4
  • Ctrl + Alt + 1-4
  • Ctrl + Alt + F1-F4

Though none of those worked. It might very well be that one of those is the correct shortcut, but PuTTy is not sending them because either PuTTy or Windows itself is handling it (Like Alt + F4).


It looks like the Debian installer might use the well-known screen utility to implement multiple tabs on a serial console, so use its key combinations to switch tabs:

Ctrl+A, then 1-4

An alternative tool for the same purpose is tmux, which might be newer than screen... but apparently screen is a GNU project and tmux might be BSD. I would guess that screen is still the more widespread one. Debian is likely to prefer GNU software anyway.

Some other distribution might use tmux instead, and its basic key combinations are very similar to screen's, but the prefix key combination is Ctrl+B instead of Ctrl+A.

  • Ctrl + A, then 1-4 did work! – BrainStone Aug 2 at 11:22
  • So the installer either uses screen to implement the "tabs" on a serial console, or reuses its key combinations since they are expected to be reasonably familiar to serious terminal users. Makes sense. – telcoM Aug 2 at 11:24
  • Might be a good idea to add a small appendum to your answer, pointing out that it's Ctrl + A and not Ctrl + B. – BrainStone Aug 2 at 11:26
  • Just as easy to rewrite the whole answer to take out the ambiguity, while leaving information on the tmux keystrokes too, in case it helps someone with a similar problem on a different distribution. – telcoM Aug 2 at 11:39

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