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jonathanserafini
Asked: 2011-05-14 04:51:31 +0800 CST

Garbled using from Dell Drac for serial console redirection

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I'm trying to get my DRAC 5 card to do serial console redirection so that I can SSH into it and access the server's bios / grub / bootup / console.

So far, I can see/edit the bios, however as soon as grub starts the output get's all jumbled up. I'm assuming this may be configuration related (though at this point I can't see what).

Configs so far are :

BIOS

  • Console redirection over Com2
  • Type : vt100/vt200
  • No redirect after boot

Grub2 on Ubuntu 10.04

  • serial --unit=1 --speed=115200 --word=8 --parity=no --stop=1
  • terminal --timeout=30 serial console
  • (kernel line :: ) linux /vmlinuz-2.6.32-31-server root=/dev/mapper/sys-dom0 ro console=tty1 console=ttyS1,115200n8r

The output itself, ends up appearing like :

��g������Bp)���'����-���C�i))a�R!{���ņ�BC!�?�i滑�����R!{���ņ߅C!'�����뤄����d�"�m�+-o�q��1Τ�Χ�+�ᤄ0�����餄����d�"?C!���s�����k뤄����d�"?C!��9u��!!!!��9�R!a���Ç$ �����i���r��:�R����B������d�"���!{�u����BS���/a�S�ć�3ߤ儤�S�����i�ąbi%)����������ąbi%)-���!)!��)������+�)�Ƥ�!����s!1Φ�r!����?/+��)))+))���!���������k������+a

I know there are settings specific for Xen, and I'll worry about those later. At this stage, I really need to get GRUB available so that I can test custom kernels. Either the kernel's I've been trying are failing or "grub-set-default" does nothing.

Annoying thing is, on a newer server / DRAC combo the configs work fine with the same version of Ubuntu, go figure -_-

Any ideas, troubleshooting steps, etc... would be a lifesaver.

linux console drac

3 Answers

  1. Best Answer

    Looks like the bios and your serial client are using a different baud-rate as the 115k2 used by grub. Or the word-size doesn't match. Has to be something like that. Maybe the newer server defaults to (or is configured for) 115k2 in Bios redirect/drac, but the other one is not ? Without experience with DRAC or DELL bios redirects (we are a HP shop here) I can't tell for sure but I think you will have to look there instead of at the Ubuntu installation.

    • 3

  2. For anyone ever needing the info .. on the Dell PE 2950, to get console redirect to work for BIOS + GRUB + OS on Ubuntu 10.04 :

    1. F2 on bootup for BIOS

    2. In Serial Console Settings :

      • Console redirection over Com2
      • Type : vt100/vt200
      • No redirect after boot
      • Speed : 57600

    3. Edit GRUB configs in /etc/default/grub

      • GRUB_CMDLINE_LINUX="console=tty1 console=ttyS1,57600n8"
      • GRUB_TERMINAL=serial
      • GRUB_SERIAL_COMMAND="serial --unit=1 --speed=57600 --word=8 --parity=no --stop=1"

    4. update-grub

    5. Create /etc/init/ttyS1.conf

      • start on stopped rc RUNLEVEL=[2345]
      • stop on runlevel [!2345]
      • respawn
      • exec /sbin/getty -h -L -8 57600n8 ttyS1 vt100

    6. Reboot.

    • 2

  3. On a Dell PowerEdge 310 with an iDRAC 6 card running Ubuntu 10.04 (Lucid) I was able to get my serial port working by making the following changes in the BIOS

    • Console redirect over COM2
    • Type vt100/vt200
    • Speed 115200

    I then made sure that the RAC was configured for a bit rate of 115,200 by logging in to the system and running the following racadm commands

    • racadm config -g cfgSerial -o cfgSerialBaudRate 115200
    • racadm config -g cfgSerial -o cfgSerialBaudRate 1
    • racadm config -g cfgSerial -o cfgSerialSshEnable 1
    • racadm config -g cfgSerial -o cfgSerialCom2RedirEnable 1 (This seems to be different from the redirection enable setting in the BIOS)
    • racadm config -g cfgSerial -o cfgSerialConsoleIdleTimeout 300
    • racadm config -g cfgSerial -o cfgSerialTelnetEnable 0
    • racadm config -g cfgIpmiSol -o cfgIpmiSolEnable 1
    • racadm config -g cfgIpmiSol -o cfgIpmiSolBaudRate 115200

    After doing all of this I installed the init script that delerious010 suggested and still wasn't able to get an SSH connection to the console via the DRAC card. I followed user92395's suggested and dropped the bit rate to 19,200 bps and, lo and behold, I was able to connect to my console port. Unfortunately for me the Dell toolkit hasn't been ported to Lucid and I couldn't find the source so I wasn't able to run 'syscfg csp'. I did find however that by modifying the /etc/init/ttyS1.conf script and adding a pre-start directive that runs the setserial command that I could increase the bit rate and connect at 115,200 bps. My ttyS1.conf script looks like this:

    # ttyS1 - getty
#
# This service maintains a getty on ttyS1 for console 
# redirection to the Dell DRAC card.

start on stopped rc RUNLEVEL=[2345]
stop on runlevel [!2345]

respawn
pre-start script
  /bin/setserial /dev/ttyS1 uart 16550A port 0x02f8 irq 3 baud_base 115200 spd_normal skip_test
end script

exec /sbin/getty -h -L 115200n8 ttyS1 vt100

    When I get a chance I'm going to boot this system with Ubuntu 12.04 (Precise) and run the syscfg command to see what the value of that 'msgcommbitrate' variable is.

    • 2