Serial Port already in use... how can I release it? Fedora

blythedj · 06-13-2007, 02:54 PM

I am using a laptop with Fedora on it. I'm trying to use minicom to connect to a Cisco router. I want to use ttyS0 (Com1) but I think its being used by another program. I ran this command:
dmesg | grep tty and got this output:
Xen Virtual console successfully installed as ttyS0.

Do I need to run some command to release this com port? I ended all Xen processes but I still get this error.

Any ideas?

macemoneta · 06-13-2007, 03:23 PM

Check your /etc/grub.conf for the Xen kernel you are running. Change the console options to remove ttyS0.

blythedj · 06-13-2007, 03:42 PM

Ok, I edited grub.conf and this is what I saw. I didn't really see anything related to ttyS0.
Am I missing something?

# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You have a /boot partition. This means that
# all kernel and initrd paths are relative to /boot/, eg.
# root (hd0,0)
# kernel /vmlinuz-version ro root=/dev/VolGroup00/LogVol00
# initrd /initrd-version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu

title Fedora Core (2.6.18-1.2849.fc6xen)
root (hd0,0)
kernel /xen.gz-2.6.18-1.2849.fc6
module /vmlinuz-2.6.18-1.2849.fc6xen ro root=/dev/VolGroup00/LogVol00 rhgb quiet
module /initrd-2.6.18-1.2849.fc6xen.img
title Fedora Core (2.6.18-1.2798.fc6xen)
root (hd0,0)
kernel /xen.gz-2.6.18-1.2798.fc6
module /vmlinuz-2.6.18-1.2798.fc6xen ro root=/dev/VolGroup00/LogVol00 rhgb quiet
module /initrd-2.6.18-1.2798.fc6xen.img

----EOF-------

macemoneta · 06-13-2007, 03:54 PM

It must be defaulted. You can try specifying another console option (e.g., console=tty). See the Fedora Xen documentation for the serial console settings.

By the way, you are intentionally running the Xen hypervisor, right? I've run into several folks that have installed this kernel when they have no intention of running Xen.

macemoneta · 06-13-2007, 03:59 PM

I found this in the Xen Wiki:

Quote:

To prevent Xen from taken the ttyS0 as a virtual console add in grub to kernel console=vga and add to module xencons=tty

This will give following waring in dmesg

WARNING: Failed to register Xen virtual console driver as 'tty1'

blythedj · 06-13-2007, 03:59 PM

I never even wanted this Xen stuff. From what I'm seeing, it is primarily for running and managing virtual machines. This was never on my to-do list with this laptop. If uninstalling Xen will work, I would like to do that too.

blythedj · 06-13-2007, 04:43 PM

I uninstalled Xen from the add/remove software list and this is what I got when I rebooted:

root (hd0,0)
Filesystem type is ext2fs, partition type 0x83
kernel /xen.gz-2.6.18-1.2849.fc6

Error 15: File not found

Press any key to continue

Now it wont even boot anymore

Is there a fix for this?