wiki:telehouse_serial_access

Version 12 (modified by Daniel Kahn Gillmor, 13 years ago) (diff)

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How do I connect to a Telehouse server via the serial port?

At Telehouse, we have installed an Octopus 550 in sylvia, a domU that is installed on Octavia. An Octopus 550 is a pci card that has 8 serial lines coming out of it. Octavia already has two built-in serial lines. Octavia's first built-in serial line is outputting a getty for Octavia itself. The second built-in serial line is going to shadow. The remaining 8 serial lines are connected to other servers in our rack.

  • Out:
    • octavia's bootloader, hypervisor console, kernel console, and getty run on built-in serial port 1, (octavia: ttyS0)
  • In:
    • shadow (built-in serial port 2, sylvia: ttyS0)
    • viewsic (octopus 1, sylvia: ttyS1)
    • malcolm (octopus 2, sylvia: ttyS2)
    • chavez (octopus 3, sylvia: ttyS3)
    • gramsci (octopus 4, sylvia: ttyS4)
    • sontag (octopus 5, sylvia: ttyS5)
    • menchu (octopus 6, sylvia: ttyS6)
    • leslie (octopus 7, sylvia: ttyS7)
    • evo (octopus 8, sylvia: ttyS8)

The serial consoles of the attached machines are all remotely accessible (to properly-authenticated people), and they are also logged and timestamped. We are using cereal to do this cleanly and easily.

In order to connect via serial console to one of the servers named above, ssh into console.mayfirst.org as servername-console

For example:

ssh -t leslie-console@console.mayfirst.org cereal attach leslie

Would give you full read/write access to the console on leslie.

The SSH RSA host key for console.mayfirst.org should have a fingerprint of:

2048 04:18:0f:cc:c9:2e:79:78:2e:91:f0:f2:f4:67:90:f8 console.mayfirst.org,209.51.172.10

We can also setup additional users that have read-only access to the sessions created by each of these usernames.

In addition - we have a serial line running from leslie's /dev/ttyUSB0 that goes to octavia's built-in serial port 1, so that octavia's console itself is remotely accessible, and logged. You can connect to octavia's console with:

ssh -t octavia-console@leslie.mayfirst.org cereal attach octavia