Power5 9133-55A Serial Console connection issue

Hey All,

Trying to connect to the Power5 9133-55A serial console using a serial-to-usb converter (RS232). The other end is connected via null modem. Tried minicom, putty and other Linux utilities, no luck. The serial device shows up as /dev/ttyUSB0.

Tried 9600 8N1 XON/XOFF, no luck. There is simply no output on the screen and no change after pressing enter multiple times.

The 9133-55A is currently hooked up to an HMC and works fine that way but not via serial.

Could someone who has done this via Linux nudge me along and let me know what settings you used? Going to retry with putty and windows as alot of the videos indicate and post if it was successful.

Cheers,
DH

---------- Post updated at 12:54 PM ---------- Previous update was at 12:41 PM ----------

Sorry for bad subject. Can a moderator please change it to "Power5 9133-55A Serial Console connection issue"?

Does this work?

How to connect to an IBM Power5 server through a Serial Cable and PuTTY - YouTube

This is the device I'm using:

Feb 13 13:50:44 mbpc-pc kernel: ftdi_sio ttyUSB0: FTDI USB Serial Device converter now disconnected from ttyUSB0

Tried from Windows using putty, but not output on screen.

Cheers,
DH

---------- Post updated at 02:05 PM ---------- Previous update was at 02:03 PM ----------

Thanks hicksd8, that's one of the things I tried, watching the Brian Smith videos and other videos but no luck. Not even through putty in windows. Anyway to detect the serial settings?

Cheers,
DH

I'm not a Power5 expert but if you read this

it talks about system ports being disabled if the HMC is connected. I don't know if that's relevant.

---------- Post updated at 07:11 PM ---------- Previous update was at 07:09 PM ----------

Also, Brian Smith uses a baud rate of 19200.

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I set the speed using the below after powering the P5 down:

stty -F /dev/ttyUSB0 19200
stty -F /dev/ttyUSB0

Then connected via putty. Worked good. I had unplugged the HMC cables earlier while the system was running and that didn't make a difference. When I had established the console session, I plugged the power cables into the Power5 again and watched the messages:

S1>
You have logged out.
.....

It logged me out of the console ASMI. The thought that the HMC connection might disable the console port seamed like an odd thing to do to me so didn't consider to test it, even though it crossed my mind. I also tried to unplug the ethernet cables from the HMC ports to see if the serial ports would be reenabled but it doesnt' work in reverse. Once you power the Power5 server on or plug in the HMC cables, either action has the effect of permanently disabling the serial ports. Strange design but ok.

Hope this helps anyone else looking.

Cheers,
DH

Both the serial connection and the network connection (to the HMC) are handled by the "Service processor" (which is about the same as a PCs ILO.board combined with some BIOS functionality). Because the HMC provides a serial console via the HMC web interface ("Open console terminal") the serial port is disabled when the system is connected (and recognized) by a HMC. Because the HMC is a separate machine and could go down, be reinstalled, etc., the system remembers that it is connected to one and stays that way even if the HMC is not connected (this is why it did not revert when you unplugged the network).

There are methods to deconfigure a configured HMC on the system (this is for POWER 7, but POWER5 is practically identical). You need to use the "pocket-calculator"-like device hanging ususally out of the system for that. (IIRC waiting also helps, but takes 14 days since the last HMC connection.)

Sometimes in the transition between POWER4 and POWER5 the speed of the console was set from 9600 u,1,p to 19200 u,1,p. Its been a long time since but as far as i remember all the POWER5 and some of the POWER4 were on 19200, the systems before are all using 9600, the systems after that are all 19200.

I hope this helps.

bakunin

2 Likes

Very kool. Thanks guy's for all the feedback. Really great answers on this.