Proxmox enable SOL access to ASRock Rack

I had some trouble enable the SOL (Serial-Over-LAN) access to my ASRock Rack motherboard. Here’s how I finally managed to get it working.

First start off by configuring “Serial Console Redirection” in the BIOS with the following settings (credit to pvalkone at GitHub):

|  SOL                                               |Emulation: ANSI:         |
|  Console Redirection Settings                      |Extended ASCII char      |
|                                                    |set. VT100: ASCII char   |
|  Terminal Type           [VT100]                   |set. VT100+: Extends     |
|  Bits per second         [115200]                  |VT100 to support color,  |
|  Data Bits               [8]                       |function keys, etc.      |
|  Parity                  [None]                    |VT-UTF8: Uses UTF8       |
|  Stop Bits               [1]                       |encoding to map Unicode  |
|  Flow Control            [None]                    |chars onto 1 or more     |
|  VT-UTF8 Combo Key Sup   [Enabled]                 |-------------------------|
|  Recorder Mode           [Disabled]                |<>: Select Screen        |
|  Resolution 100x31       [Disabled]                |^v: Select Item          |
|  Legacy OS Redirection   [80x24]                   |Enter: Select            |
|  Putty KeyPad            [VT100]                   |+/-: Change Option       |
|  Redirection After BIO   [Always Enable]           |F1: General Help         |
|                                                    |F7: Discard Changes      |
|                                                    |F9: Load UEFI Defaults   |
|                                                    |F10: Save and Exit       |
|                                                    |ESC: Exit                |

From your client (where you have installed ipmitools ):

➞ ipmitool -I lanplus -H <bmc-mgmt-ip> -U admin -e \& sol info 1
Set in progress                 : set-complete
Enabled                         : true
Force Encryption                : false
Force Authentication            : false
Privilege Level                 : USER
Character Accumulate Level (ms) : 60
Character Send Threshold        : 96
Retry Count                     : 7
Retry Interval (ms)             : 500
Volatile Bit Rate (kbps)        : 115.2
Non-Volatile Bit Rate (kbps)    : 115.2
Payload Channel                 : 1 (0x01)
Payload Port                    : 623

Make sure that Volatile Bit Rate (kbps) and Non-Volatile Bit Rate (kbps) is set to 115.2 (115200).

Restart the server and login. Edit /etc/default/grub and change GRUB_CMDLINE_LINUX_DEFAULT, GRUB_TERMINAL and GRUB_SERIAL_COMMAND:

GRUB_CMDLINE_LINUX_DEFAULT="console=ttyS1,115200n8 console=tty0"
GRUB_TERMINAL="serial console"
GRUB_SERIAL_COMMAND="serial --speed 115200 --unit=1 --word=8 --parity=no --stop=1"

After saving the file, do not forget to run update-grub.

Then we need to tell systemd to start serial ttyS1 on boot.

Optional, it can be worth changing the default serial-getty@.service to only accept 115200 as baud-rate, as according to Roger Irvin. Do this by coping the default service to /etc/systemd/system/.

cp /lib/systemd/system/serial-getty@.service /etc/systemd/system/

Then change the ExecStart line from:

ExecStart=-/sbin/agetty -o '-p -- \\u' --keep-baud 115200,38400,9600 %I $TERM


ExecStart=-/sbin/agetty -o '-p -- \\u' 115200 %I $TERM'

Save the file, reload systemd daemon, start and enable ttyS1:

systemctl daemon-reload
systemctl start serial-getty@ttyS1
systemctl enable serial-getty@ttyS1

Reboot the server, and use ipmitool to get a SOL session:

ipmitool -I lanplus -H <bmc-mgmt-ip> -U admin -e \& sol activate

To exit the session type &. (no enter!) and the session is terminated.