cross-connecting console ports?

2010-05-17 Thread Miles Fidelman

Hi Folks,

I have two rack-mounted servers located in a datacenter, running Debian 
Lenny.  Every once in a while, in order to install stuff, I have to 
physically go to the data center and connect a terminal to one server or 
the other.


Short of buying a remote KVM, it occurs to me that it might be possible 
to cross-connect the serial ports on the two computers - using a 
terminal program on one, to access the other, and vice versa.


Has anybody done this?  Any suggestions on where to start - both re. 
cabling (USB vs. serial cross-over), and/or software?


Thanks very much,

Miles Fidelman

--
In theory, there is no difference between theory and practice.
Infnord  practice, there is.    Yogi Berra



--
To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org 
with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org

Archive: http://lists.debian.org/4bf1ae3a.2000...@meetinghouse.net



Re: cross-connecting console ports?

2010-05-17 Thread Robert Brockway

On Mon, 17 May 2010, Miles Fidelman wrote:

Has anybody done this?  Any suggestions on where to start - both re. cabling 
(USB vs. serial cross-over), and/or software?


Hi Miles.  Many of us have done this for years and years.  You can go with 
a serial console over rj45 (including bios level tools) like iLO or DRAC 
or you can get Linux to provide you with a 'software serial console' that 
will be available from the bootloader (lilo or grub) onwards.


A quick Google should turn up howtos on how to configure Grub  friends.

I've always used true serial ports to do this although I understand it is 
possible via usb-serial connectors.


You can use any serial terminal app to provide access to the serial port. 
I prefer minicom but there are lots of options.


Keep security in mind when doing this.  If soneone gets root access[1] to 
one of the servers then they can 0wn the other one.  Don't cross-connect 
the serial consoles unless the servers are in the same 'security domain'.


[1] You can restrict who can talk to minicom for example.

Cheers,

Rob

--
Email: rob...@timetraveller.org Linux counter ID #16440
IRC: Solver (OFTC  Freenode)
Web: http://www.practicalsysadmin.com
Open Source: The revolution that silently changed the world


--
To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org 
with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org

Archive: 
http://lists.debian.org/alpine.deb.1.10.1005171708120.7...@castor.opentrend.net



Re: cross-connecting console ports?

2010-05-17 Thread Andy Smith
Hi Miles,

On Mon, May 17, 2010 at 04:59:38PM -0400, Miles Fidelman wrote:
 Short of buying a remote KVM, it occurs to me that it might be possible  
 to cross-connect the serial ports on the two computers - using a terminal 
 program on one, to access the other, and vice versa.

This works fine; I do it all the time when testing hardware.

 Has anybody done this?  Any suggestions on where to start - both re.  
 cabling (USB vs. serial cross-over), and/or software?

These days it becomes easier to have a bunch of USB ports than a
bunch of serial ports, so USB/serial converters are cheap and useful
and I've yet to find one that doesn't just work under Debian.

I used to use minicom, but lately I use screen /dev/ttyUSB0 9600
or whatever.

Cheers,
Andy

-- 
http://bitfolk.com/ -- No-nonsense VPS hosting


signature.asc
Description: Digital signature