Accessing the SunFire V100 LOM Serial Console

Unlike traditional “Intel” or PC based servers (HP Proliant, IBM xSeries, Dell PowerEdge, etc.) the SUN SunFire is a RISC server and does not use keyboard, mouse or monitor ports with which to interact with the server. Interactions traditionally takes place through the integrated Lights Out Management, or LOM, port which provides, in addition to a serial console session, basic hardware manipulation – most importantly the ability to power on and power off the device.

Attaching to the LOM port on the back of the V100 requires a console cable. The LOM port itself is an RJ45 port (the same as is commonly used for copper Ethernet connections) and uses RS232 serial communications. For most casual SunFire users the best means of attaching to this connection is to use an RJ45 to DB9 serial cable that can be used to attach to the serial (DB9 Male) connection on most normal personal computers.

Console cables can be purchased cheaply enough (try eBay) or you can make your own. But they are so cheap that I would suggest buying a real SUN cable on eBay. I spent $10. It was worth the money to avoid the headache. If you enjoy making your own cables then be my guest.

If you are using a Windows based PC then the most popular tool for connecting to the console session is Hyperterminal. Hyperterminal is popular and easy to use and is part of the stock Windows operating system so no additional software is necessary. I don’t use Windows myself and am unaware of any known quirks with using Hyperterminal for this tasks. If you are a Windows Vista user then you are out of luck. Microsoft has removed Hyperterminal from its latest OS offering and has not replaced its functionality. Vista is simply lacking in this industry critical functionality. You can complain. Or you can migrate to Linux.

I use a Linux based PC (HP dx5150 running OpenSUSE 10.1 for AMD64 if you must know.) My preferred serial communications tool (by preferred I mean “the one that I know”) is Minicom. has a good Minicom Remote Serial Console How-To. Minicom is easy to use and acts, more or less, just like a standard console window making it extra transparent to you, the end user. It also makes it easy to access your LOM remotely by connecting via SSH to your Linux desktop and access the LOM via Minicom in your SSH session. Much easier than running Hyperterminal over an RDP session.

The RS232 serial settings for the LOM (or the serial ports) are simple:

  • 9600 baud
  • 8 bits
  • No parity
  • 1 stop bit
  • No handshaking

Fire up Minicom (use minicom -s to set the settings) and you should be dropped immediately to the LOM prompt. From here you can type help to get a command list or poweron to turn on your V100 without needing to touch the power switch. Once the V100 has turned on the LOM will automatically pass through the server console and it will be exactly as if you were sitting directly at a terminal attached to the server (which is, of course, another option.)

At any time when using the V100 console that you wish to return to the LOM itself you may do so using the “#.” key sequence. That is “pound-period”.

Note: The SUN Configuring ALOM Document has some good info on the serial settings and on how to build your own console cable.

Learn more about the SunFire V100 from Scott Alan Miller’s V100 page.

6 thoughts on “Accessing the SunFire V100 LOM Serial Console”

  1. That is true if you are connecting to a terminal server like those from Cisco or Uplogix. But I am connecting directly to a DB9 serial connector on a Linux workstation and there is no such thing as a “standard” RJ45 to DB9 cable. So the cables are specially made to be the right wire combination for the console to the serial connector on the PC.

  2. I think what he meant was you can buy an adapter (sorry, don’t have the Sun P/N) that is DB9 female to RJ45. You plug this into your PC serial port and then you can run straight double-ended RJ45 cable to your server. The adapters are about 3 bucks if you look around

  3. Yeah, “straight” double ended isn’t what people think that it is. RJ45 is just the connector on the end. CAT5 and CAT6 are a specific standard and not all cables with RJ45 ends have the same configuration and the “standard” is not “straight.” A straight cable would not work with the normal adapters.

  4. You can connect using PuTTY too, which is probably the most standard tool for this on Windows today. Same settings as above.

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