Log Files Overview - Red Hat ENTERPRISE LINUX 5 - VIRTUALIZATION GUIDE Manual

Chapter 33. Troubleshooting Xen
• ifconfig
• tcpdump
The tcpdump command 'sniffs' network packets. tcpdump is useful for finding network
abnormalities and problems with network authentication. There is a graphical version of tcpdump
named wireshark.
• brctl
brctl is a networking tool that inspects and configures the Ethernet bridge configuration in the
Virtualization linux kernel. You must have root access before performing these example commands:
# brctl show
bridge-name bridge-id
-----------------------------------------------------------------------------
xenbr0
xenbr1
xenbr2
# brctl showmacs xenbr0
port-no mac-addr
1 fe:ff:ff:ff:ff:
2 fe:ff:ff:fe:ff:
# brctl showstp xenbr0
xenbr0
bridge-id
designated-root
root-port
max-age
hello-time
forward-delay
aging-time
hello-timer
topology-change-timer
Listed below are some other useful commands for troubleshooting virtualization on Red Hat Enterprise
Linux 5. All utilities mentioned can be found in the Server repositories Red Hat Enterprise Linux 5.
• strace is a command which traces system calls and events received and used by another process.
• vncviewer: connect to a VNC server running on your server or a virtual machine. Install vncviwer
using the yum install vnc command.
• vncserver: start a remote desktop on your server. Gives you the ability to run graphical user
interfaces such as virt-manager via a remote session. Install vncserver using the yum install
vnc-server command.

33.2. Log files overview

When deploying Red Hat Enterprise Linux 5 with Virtualization into your network infrastructure, the
host's Virtualization software uses many specific directories for important configuration, log files, and
other utilities. All the Xen logs files are standard ASCII files, and accessible with a text editor:
350
STP enabled
8000.feffffff no
8000.ffffefff yes
8000.ffffffef no
8000.fefffffffff
8000.fefffffffff
0
20.00
2.00
0.00
300.01
1.43
0.00
interfaces
vif13.0
pddummy0
vif0.0
local? aging timer
yes 0.00
yes 0.00
path-cost
bridge-max-age
bridge-hello-time
bridge-forward-delay
tcn-timer
gc-timer
0
20.00
2.00
0.00
0.00
0.02