Chapter 37. Troubleshooting the Xen para-virtualized drivers
This chapter deals with issues you may encounter with Xen hosts and fully virtualized Red Hat Enterprise Linux guests using the para-virtualized drivers.
37.1. Red Hat Enterprise Linux 5 Virtualization log file and directories
Red Hat Enterprise Linux 5 Virtualization related log file
In Red Hat Enterprise Linux 5, the log file written by the xend daemon and the qemu-dm process are all kept in the following directories:
/var/log/xen/- directory holding all log file generated by the
xenddaemon and qemu-dm process. xend.log- This logfile is used by xend to log any events generate by either normal system events or operator initiated events.
- virtual machine operations such as create, shutdown, destroy etc are all logged in this logfile.
- Usually this logfile will be the first place to look at in the event of a problem. In many cases you will be able to identify the root cause by scanning the logfile and review the entries logged just prior to the actual error message.
xend-debug.log- Records error events from xend and its subsystems (from the framebuffer and Python scripts)
xen-hotplug.log- Logs events from hotplug events.
- Event notifications from devices not coming online or network bridges not online are logged in this file.
qemu-dm.PID.log- This file is created by the
qemu-dmprocess which is started for each fully virtualized guest. - The
PIDis replaced with thePIDof the process of the related qemu-dm process - You can retrieve the
PIDfor a givenqemu-dmprocess using thepscommand and in looking at the process arguments you can identify the virtual machine theqemu-dmprocess belongs to.
If you are troubleshooting a problem with the virt-manager application you can also review the logfile generated by it. The logfile for virt-manager will be in a directory called
.virt-manager in the user's home directory whom ran virt-manager. This directory will usually be ~/.virt-manager/virt-manager.
Note
The logfile is overwritten every time you start virt-manager. If you are troubleshooting a problem with virt-manager make sure you save the logfile before you restart virt-manager after an error has occurred.
Red Hat Enterprise Linux 5 Virtualization related directories
There are a few other directories and files which may be of interest when troubleshooting a Red Hat Enterprise Linux 5 Virtualization environment:
/var/lib/libvirt/images/- the standard directory for file-based guest images.
/var/lib/xen/xend-db/- directory that hold the xend database which is generated every time the daemon is restarted.
/etc/xen/- Stores a number of configuration files for the Xen hypervisor.
/etc/xen/xend-config.sxpis the main configuration for the xend daemon. Thexend-config.sxpfile enables or disables migration and other features not configured bylibvirt. Use thelibvirttools for all other features.
/var/lib/xen/dump/- Holds dumps generate by virtual machines or when using the
xm dump-corecommand. /proc/xen/- Stores
xen-kernelinformation in the following files:/proc/xen/capabilities/proc/xen/privcmd/proc/xen/balloon/proc/xen/xenbus/proc/xen/xsd_port/proc/xen/xsd_kva
