Version 35 (modified by Jamie McClelland, 12 years ago) (diff)


How do I connect to an MF/PL server located at Telehouse via the serial port?

Note: if you are trying to connect to a server in our XO/Bandcon, see our XO serial access page.

Serial Console physical setup

In the MF/PL Telehouse rack, we have installed two Octopus 550's 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 the console for octavia itself. The second built-in serial line is reserved (it will probably be used to control a power system). The remaining 16 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:
    • reserved (built-in serial port 2)
    • Octopus (Top, IRQ 19)
      • naomi (Cable 1, sylvia: ttyS0)
      • malcolm (Cable 2, sylvia: ttyS1)
      • chavez (Cable 3, sylvia: ttyS2)
      • gramsci (Cable 4, sylvia: ttyS3)
      • sontag (Cable 5, sylvia: ttyS4)
      • menchu (Cable 6, sylvia: ttyS5)
      • leslie (Cable 7, sylvia: ttyS6)
      • evo (Cable 8, sylvia: ttyS7)
    • Octopus (Bottom, IRQ 20)
      • shadow (Cable 1, sylvia: ttyS8)
      • goofball (Cable 2 sylvia: ttyS9)
      • tenant (Cable 3 sylvia: ttyS10)
      • NOT IN USE (Cable 4 sylvia: ttyS11)
      • algernon (Cable 5 sylvia: ttyS12)
      • sprocket (Cable 6 sylvia: ttyS13)
      • NOT IN USE (Cable 7 sylvia: ttyS14)
      • fred (Cable 8 sylvia: ttyS15)

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.

How to connect

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

For example:

ssh -t cereal attach leslie

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

The SSH RSA host key for should have a fingerprint of:

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

We can also setup additional users that have read-only access to the sessions created by each of these usernames, should that be desirable. You can request such access by creating a ticket.

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 cereal attach octavia

and controls the serial console of gabriel?, our Baytech RPC-4. To get access to gabriel, do:

ssh -t cereal attach gabriel

Setting up a new console user

To setup a new console user (this is something only admins can do), do the following as root@sylvia:

adduser --disabled-password --gecos='fred console user,,,' fred-console
cereal-admin create fred /dev/ttyS15 115200 fred-console fred-console
cereal-admin start fred