As a follow-up to my last post, I'm also using this application to help set up new Linux VM machines. 

On the first boot I run a script that tries to pull info from /dev/ttyS3 and put it into shell variables.  These variables contain the IP address, netmask and other such info the machine needs to set itself up.  I could address this with a combo of DHCP and tftp, but I didn't want to.

Once I get a script I'm less ashamed of I'll post all the details.

I recently started using socat for serial console as well.  Here's the command that worked for me to kill local echo and send each character individually instead of a line at a time (guest OS is OpenBSD 3.8, so I named the socket com0 after what it's called in OpenBSD):

Re: Access VM Serial Console - Named Pipe TCP Proxy Utilitysocat unix-connect:com0 stdio,echo=0,raw[/code]

The one caveat to this that I've found is that ^C and ^D are both passed to the socket rather than to socat, so in order to shut down the console connection you either have to exit the VM or kill socat explicitly ('pkill socat' does just fine on machines with pcre installed).  It's probably also a good idea to pay attention to the terminal type (presumably xterm) so you can deal with the guest OS accordingly.

Re: Access VM Serial Console - Named Pipe TCP Proxy UtilityEdit:[/b] I dug through the man page a little, looking for a way to replicate the TCP method described above, but I couldn't find a way to suppress the echo or use per-character transmission on a TCP socket (using the tcp4-listen: transport).  If anyone can find a way to do this, it does offer the advantage of being able to detach using the telnet escape (^]) sequence.

Message was edited by:

        yumenohikari

I'm trying to solve a VM-MultiIO card incompatability that socat might solve.  What do you think:

I have a multi-io card (9 serial ports) called ttyQ1a1 - ttyQ1a8 which work great on the linux host, BUT, the Windows VM's will not recognize the serial ports.  Would it be possible to attach a serial port to a named pipe in the Windows VM, and then attach the named pipe to the linux tty using socat?

If so, can you suggest the parameters?  (I'm lost in the socat documentation)

Thanks!

Wow!

Thank you all very much for the idea of using socat! It did work like a magic. Thank you all once more!

I want to send all RH4/5 Linux guest console output to a log file. I don't care if this file is on the Linux guest itself or a centralized linux monitoring server. I don't want the file to be on the host. Ttylog says it can't do consoles. I've tried ttywatch for a while now and nothing ever gets sent to its own logfile. I've tried to compile ttywatch myself and dag's precompiled RPM for my specific linux versions. I'm starting to think that ttywatch should not be run on the linux guest and cannot monitor/intercept outbound serial traffic, just inbound. Correct me if I'm wrong. I can't find much help on ttywatch and most of it says to use a null-modem cable. Screw that, this is a virtual world, and I'm not hooking up any null-modem cables!

I added the options: console=tty1 console=ttyS0 to the end of my kernel line in /boot/grub/grub.conf and when I boot up the output does go to a file I specify on the host that I configured using the second option in guest serial port creation (Use output file). Unforntunately, this file can't be viewed while the guest is running (tail/cat's fail) contrary to the suggestion in this link ("tail -f foo"):

http://blackmagic02881.wordpress.com/

So now I'm thinking socat, but I can't find any help/examples on sending socat output to a file. I don't even understand the examples above.

For example "socat unix-connect"? What is unix-connect?

And then "socat -d -d -d /var/lib/vmware/Virtual\ Machines/vmtestcli5/serial2tcp4-listen:9988", what is with the "/Virtual\"

and "Machines"? Where are these files/directories? I'm using ESX and I can't find them. Under /var/lib/vmware is the hostd directory. I tried creating a named pipe called "serial1" and if I drop down to "/" on both my host and guest, and do a find, I can't find it. So, if anybody can provide some basic, step by step help on how I can accomplish this with ttywatch or socat, that would be great.

There was too much "VMware host machine", "vmware host server", "local machine" in jackalope's post. So please make sure each command you specify clearly describes from where it is supposed to run.

We are running ESX 3.0.1 & 3.0.2. So let's say the ESX server is called Fred and the Linux Guest is called Bob, and a third Linux monitoring server is called Sarah. Sarah is where I want the logfile of Bob's console output. I'm guessing socat needs to run on Fred as a pass-through and then another socat on Sarah to receive the incoming data and send (fork?) to a file?

I'm guessing esxcfg-firewall needs to be run to allow some of this port writing.

Finally, how exactly does the serial port need to be setup in ESX for the Linux Guest. The post above says to name the file ./serial1 (why the ./?), and "this end is the server" "the other end is an application". Well in ESX it is called the near end and the far end (which end is my linux guest, the near or the far end??? very confusing) and there is no "application" option, the "Far end:" options are "A process" and "A virtual machine". So I'm really not following the difference or how each would be useful?

Sorry for the lengthy post, but I just can't find any information out there on anybody doing this. Isn't it frustrating when some boot-up script fails and only sends its failure to the screen (not the boot.log file) and then it scrolls by too fast. I think vmware should allow us to scroll back in their console that would be very helpful as well (shouldn't be too hard for them to detect that it is only text and not a GUI screen). I'll create a new topic if this doesn't get too much visibility as I'm not really wanting Serial Console Access, but it was the only discussion close and talking about socat.

Can socat running on the linux guest intercept outbound ttyS0 traffic and send it straight to a file on the linux guest file system?

Use a version of socat compiled for EL3.  I'm just testing this now and I haven't been able to disconnect and reconnect cleanly (yet).  After the first connection is dropped, subsequent attempts to use the "named pipe" yield errors such as:

socat[5153] E connect(3, AF=1 "mypipe", 17): Connection refused