How to get fewer ttys with Systemd?

Question

In the old days I just modified /etc/inittab. Now, with systemd, it seems to start tty[1-6] automatically, how should I disable tty[4-6]?

Looks like there's only one systemd service file, and it use a %I to discern different tty sessions. I hope I don't need to remove that service, and create each getty@ttyX.service manually.

Answer 1

There is no real need to disable "extra" TTYs as under systemd gettys are generated on demand: see man systemd-getty-generator for details. Note that, by default, this automatic spawning is done for the VTs up to VT6 only (to mimic traditonal Linux systems).

As Lennart says in a blog post¹:

In order to make things more efficient login prompts are now started on demand only. As you switch to the VTs the getty service is instantiated to getty@tty2.service, getty@tty5.service and so on. Since we don't have to unconditionally start the getty processes anymore this allows us to save a bit of resources, and makes start-up a bit faster.

If you do wish to configure a specific number of gettys, you can, just modify logind.conf with the appropriate entry, in this example 3:

NAutoVTs=3

^{1. In fact the entire series of posts—currently numbering 18— systemd for Administrators, is well worth reading.}