Xen FAQ Guest Conversion
How do I convert a Centos HVM Guest to a PV Guest?
Creating a Centos HVM domU with working PV drivers : http://pastebin.com/fb6fe631 Converting HVM guest to PV guest : http://pastebin.com/f6a5022bf
If you follow both parts correctly you should have a working PV domU. If anything goes wrong during conversion process, you should still be able to boot the previous HVM domU config if you select the non-xen kernel (second entry) from grub menu.list.
I have an Xen image that was built for a graphical console (VNC). Is there any way to change it to the non-graphical console (xen console)?
For HVM guest, you need to enable serial port on domU config file (example here: http://pastebin.com/fb6fe631), and setup domU to use serial port (ttyS0 on Linux) by modifying (for Linux domU) /boot/grub/menu.lst, /etc/inittab, and /etc/securetty.
If it's PV guest, you need to set up domU to use xen console (which is xvc0 on current xen version, hvc0 on pv_ops kernel). It's similar to setting up domU for serial console, you just need to change ttyS0 to hvc0. An example of domU setup that can use both xvc0 and vnc console is here : http://pastebin.com/f6a5022bf
How do I remove an active virtual machine?
xm shutdown or xm delete
How do I run xm console to a WindowsXP DomU?
You can't xm console to that (I'm not sure you can xm console to any hvm, but I know you can't to one that doesn't have a console).
I start a new DomainU (Guest) and some text scrolls by for launching the guest but then it just sits there with Continue and no actions takes place?
The console for this new DomainU is not properly available for you; fix this by adding xtra="xencons=tty" in the configuration file. This will bring up a login screen directly for your new DomainU.
One of our CentOS 5.3 randomly reboots, at different times of the day, and I can't see why it's doing it. I have looked through the logs, but don't see any thing in there that shows me why it has rebooted. How can I debug this?
The problem is that when the box panics, it stops syslogd, so you don't get the panic output in /var/log. The best way to fix this is to setup a logging serial console.
