Enabling the Serial Console¶
TNSR can utilize a serial console on hardware containing a serial port, either directly in hardware or virtualized though a feature such as IPMI for Serial Over LAN (SOL).
Certain Netgate hardware models may ship with the hardware serial console already active. Try to access the console before performing additional steps.
Netgate appliances equipped with IPMI ship with default BIOS settings enabled for SOL operation. This applies to the 1537, 1541 and future models containing IPMI devices.
Modifying the kernel command line incorrectly can result in a system that does not boot. Take a backup before starting, and only make the changes listed in this document.
Backup the Kernel Boot Configuration¶
Enabling the serial console requires adding arguments to the kernel command line.
Backup the existing
grub configuration file:
cp /boot/grub2/grub.cfg ./grub.cfg.bak
Edit the Kernel Boot Configuration¶
/etc/default/grub with text editor (e.g.
vi). The file should look
GRUB_TIMEOUT=5 GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)" GRUB_DEFAULT=saved GRUB_DISABLE_SUBMENU=true GRUB_TERMINAL_OUTPUT="console" GRUB_CMDLINE_LINUX="crashkernel=auto resume=/dev/mapper/cl-swap rd.lvm.lv=cl/root rd.lvm.lv=cl/swap selinux=0" GRUB_DISABLE_RECOVERY="true" GRUB_ENABLE_BLSCFG=true GRUB_CMDLINE_LINUX_DEFAULT="intel_iommu=on iommu=pt sdhci.debug_quirks2=0x40"
GRUB_CMDLINE_LINUX_DEFAULT line and append the console settings.
For IPMI SOL, the terminal device will be
ttyS1. For a hardware serial
console, it would be
ttyS0. This example will use
This example enables both SOL on
ttyS1 and the VGA console on
console=ttyS1,115200n8 console=tty0 to the end of the
GRUB_CMDLINE_LINUX_DEFAULT line as shown:
GRUB_CMDLINE_LINUX_DEFAULT="intel_iommu=on iommu=pt sdhci.debug_quirks2=0x40 console=ttyS1,115200n8 console=tty0"
Adding entries for these two consoles results in boot messages being displayed on both SOL and iKVM/VGA output.
Rebuild the Kernel Boot Configuration¶
Build a new
grub.cfg using the following command:
sudo grub2-mkconfig -o /boot/grub2/grub.cfg
Reboot the system normally and the new settings will take effect.
Accessing the Serial Console¶
IPMI Serial Over LAN¶
There are multiple methods which can connect to the serial console.
The simplest method is to use the
ipmiconsole tool which is part of the
ipmiconsole -h <IPMI address> -u <username> -P
To exit the IPMI console press the following keys in sequence:
ssh to connect to the IPMI controller then launch the
serial console utility:
ssh <username>@<IPMI address> cd system1 cd sol1 start
To exit the SOL console press the following keys in sequence:
Hardware Serial Console¶
To access the hardware serial console, a serial cable connection must be established between the client and the device. This varies widely by hardware and may be a USB port, DB9 port, RJ45 style port, and may also involve a null modem adapter. Check the hardware device manual for details.
On the client device, use standard serial client software such as
minicom, or others to access the console. Consult the
serial client software documentation for additional details.
For devices sold by Netgate, the hardware manual contains information about accessing the serial console which covers hardware and software. For an example, see the manual for the Netgate 5100.