The Console control on a server's Overview tab opens a VNC session to the guest in your browser. It is out of band: it does not use SSH, does not use the server's network stack, and does not care whether the firewall is blocking everything.
What it is for
- You locked SSH out with a firewall rule or an
sshd_configmistake - The server does not finish booting and you need to see why
- The disk filled up and nothing works
- You need to type at the GRUB menu or a single-user shell
- The server has no public IPv4 at all, so SSH was never an option
Using it
Click Console. A session is minted and you are taken straight to it.
- Sessions last 10 minutes, then expire. Open another if you need longer.
- The console is available after provisioning while the server still exists. There is no console for a server that is provisioning or destroyed.
- A session is bound to the person who opened it. Handing the URL to somebody else does not let them in.
Things that surprise people
It is a screen, not a terminal. Copy and paste behave like a physical KVM, which is to say awkwardly. For long commands, get SSH working instead.
Keyboard layout is whatever the guest thinks it is. Usually US.
No scrollback. Use less, or dmesg | less.
Get in, fix SSH, get out
The console is a rescue tool. If you are living in it, the thing to fix is SSH: check the firewall first, since a DROP inbound policy with no rule for TCP 22 is the usual cause.