29.1. Debugging and troubleshooting Red Hat Virtualization
This section summarizes the System Administrator applications, the networking utilities, and the Advanced Debugging Tools (for more information on using these tools to configure the Red Hat Virtualization services, see the respective configuration documentation). You can employ these standard System Administrator Tools and logs to assist with troubleshooting:
xentop
xentop displays real-time information about a Red HAt Virtualization host system and it's domains.
xm
Using the dmesg and log
vmstat
iostat
lsof
sysstat iostat, mpstat and sar.
You can employ these Advanced Debugging Tools and logs to assist with troubleshooting:
XenOprofile
systemtap
crash
sysrq
sysrq t
sysrq w
These networking tools can assist with troubleshooting virtualization networking problems:
ifconfig
tcpdump
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 STP enabled interfaces ----------------------------------------------------------------------------- xenbr0 8000.feffffff no vif13.0 xenbr1 8000.ffffefff yes pddummy0 xenbr2 8000.ffffffef no vif0.0 # brctl showmacs xenbr0 port-no mac-addr local? aging timer 1 fe:ff:ff:ff:ff: yes 0.00 2 fe:ff:ff:fe:ff: yes 0.00 # brctl showstp xenbr0 xenbr0 bridge-id 8000.fefffffffff designated-root 8000.fefffffffff root-port 0 path-cost 0 max-age 20.00 bridge-max-age 20.00 hello-time 2.00 bridge-hello-time 2.00 forward-delay 0.00 bridge-forward-delay 0.00 aging-time 300.01 hello-timer 1.43 tcn-timer 0.00 topology-change-timer 0.00 gc-timer 0.02
Other utilities which can be used to troubleshoot virtualization on Red Hat Enterprise Linux 5. All utilities mentioned can be found in the Server repositories of the Red Hat Enterprise Linux 5 Server distribution:
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.