Custom Xen DomU
From OptionC
| Table of contents |
General Directions
We always meant to say something meaningful here, but haven't yet... honestly, this page is only about 1/4 done, at most.
Clone a running system
Copy everything but the following into a mounted LVM partition, a loop-mounted file, or an actual partition.
/proc/* /var/log/*/* /var/run/*/* /var/run/*.pid /var/tmp/* /var/lock/*/* /dev/mapper/* /tmp/* /sys/* /mnt/*/*
Modify /etc/fstab and copy modules to /lib/modules (usually from the dom0)
Build it from scratch
- Create a Debian VM with debootstrap
- Tweak it to meet your needs
- POP3 IMAP SMTP MYSQL E-mail server - This was created to show, step-by-step, how we created an e-mail server DomU VM for Xen. In reading through the document you will find that there's almost no reference to Xen or virtualization. This is how it should be. A DomU VM should be nothing more than a standalone machine in its configuration. The fact that it's running under a host machine is irrelevant.
- DNS DHCP server
- Firewall_domU_with_direct_NIC_access - Kernel configs and Xen options for a domU that has access to PCI NICs that are hidden from the dom0
- WebGUI Content Manager - Install the WebGUI Open Source Content Manager from Plain Black
- Jakarta Tomcat - Create a Jakarta Tomcat server
Prebuilt DomU
These are links we have found - we haven't actually tested all of these images, so be warned.
- Free OS Zoo images (http://free.oszoo.org/download.html)
- built for UML (http://uml.harlowhill.com/index.php/UMLRootFilesystems)
- FreeBSD5.3 (http://www.fsmware.com/xenofreebsd/5.3/)
- Jailtime.org: Virtual filesystems for Xen (http://jailtime.org/)
- xen-get.org... (http://www.xen-get.org/) "will be the central source for ready-to-run system images to use as unprivileged domains (domU)"
- XenStuff (http://sourceforge.net/projects/xenstuff/) - We have tested these; they're ours.
- Built for Xen (http://www.kvadratrot.net/~xen/) - this link was dead as of 2005-10-13... I had hopes it would come back, but it's been months now... -> Is this what you were looking for? http://ooo.sivit.fr/~anivard/www.kvadratrot.net/
Sort of on topic... here is a post on the lists about a QEMU tool (lomount (http://qemu.dad-answers.com/download/qemu/utilities/QEMU-HD-Mounter/lomount/)) that lets you mount individual partitions from a file-backed VBD/image with multiple partitions.
FAQ
How do I create a domU from an install CD/DVD?
You don't (this answer is accurate as of Xen version 2.0.6), at least, not directly. Usually it's recommended to run the installer and install into another partition (which doesn't work if you can take the system off-line or if you don't have a spare partition). Then either modify that partition to become a domU, or copy all the files and put them elsewhere.
Recommended Reading
- A nice thread from the lists on various ways to create domUs (http://lists.xensource.com/archives/html/xen-devel/2005-03/msg01221.html)
