The explanation below details the installation of a Debian guest on a Xen host running the CentOS/Red Hat Enterprise Linux 5 kernel. The Debian guest is installed in a logical volume, but with minor adjustments, a file-based image can be booted as well.
To get a Debian guest running on an CentOS host, you first need a Debian image file. If you have a running Debian system, do this as follows:
$ dd if=/dev/zero of=etch_img count=1024 bs=$[1024*1024]
$ sudo mkfs.ext3 etch_img
$ sudo mkdir deb_mnt
$ sudo mount -o loop etch_img ./deb_mnt
$ sudo debootstrap --arch x386 etch deb_mnt \
ftp://ftp.nl.debian.org/debianAfter it's done, unmount and copy the file to your CentOS Xen Host.
I haven't gotten the stock CentOS Xen-enabled kernel running with the Debian guest. So download a ready-built Xen kernel from xensource.com.
$ wget http://bits.xensource.com/Xen/latest/xen-3.0.2-install-x86_32.tgz
or for a 64-bit machine:
$ wget http://bits.xensource.com/Xen/latest/xen-3.0.2-install-x86_64.tgz
After downloading, unpack it in a special place. I suggest /opt, but some others use the /usr/local directory.
Mount the image again:
$ sudo mkdir deb_mnt $ sudo mount -o loop etch_img ./deb_mnt
Copy the /boot and /lib/modules directories from the Xen package to the virtual machine:
$ sudo cp -r /opt/xen-3.0.2-2-install/install/lib/modules/2.6.16-xen \
deb_mnt/lib/modules
$ sudo cp -r /opt/xen-3.0.2-2-install/install/boot/* deb_mnt/bootEdit the etc/fstab file and add the following lines:
/dev/xvda1 / ext3 errors=remount-ro,noatime 0 1 proc /proc proc defaults 0 0 /swapfile0 swap swap defaults 0 0
Note that the 'noatime' option and the swapfile (instead of a swap partition) are things that aren't necessary, but just personal taste.
Edit the boot/grub/menu.lst file, and adjust the contents as follows:
timeout=5
splashimage=(hd0,0)/boot/grub/splash.xpm.gz
hiddenmenu
title Debian
root (hd0,0)
kernel /boot/vmlinuz-2.6.16-xen ro root=/dev/xvda1Unmount the image:
$ sudo umount deb_mnt
Create a logical volume for the Debian guest to use:
$ sudo lvcreate -L 2G -n debian_lv vg0
Partition the new logical volume:
$ sudo fdisk /dev/vg0/debian_lv
After adding one or more partitions, write the new table and create new devices pointing to the partitions:
$ sudo kpartx -a /dev/vg0/debian_lv
Copy the image file to the partition and resize the file system to the full size that the partition allows:
$ sudo cp deb_img /dev/mapper/debian_lv1 $ sudo resize2fs /dev/mapper/debian_lv1
Create a new Xen configuration file for the Debian virtual machine, preferably in the /etc/xen directory, or if you want to start it up automatically when booting the physical host, in the /etc/xen/auto directory.
name = "debian" memory = "64" # If you want to use the image file, uncomment the line below and # of course comment the other disk line. # disk = [ 'file:/home/user/deb_img,xvda1,w', ] disk = [ 'phy:/dev/vg0/staff_lenny,xvda,w', ] vif = ['mac=00:16:3e:7b:8e:61, bridge=xenbr0, vifname=x.len0', ] vfb = ["type=vnc,vncunused=1"] uuid = "076f8df4-f2a3-452d-a628-fab3c9fbe913" bootloader="/usr/bin/pygrub" vcpus=1 on_reboot = 'restart' on_crash = 'restart'
Now start the Debian guest:
$ sudo xm create -c /etc/xen/debian
Upon the login prompt, type 'root' as the username and press enter when asked for a password.
What remains is to set the root password and fix networking by adding the following lines to /etc/network/interfaces:
auto lo iface lo inet loopback
auto eth0 iface eth0 inet static address x.x.x.x netmask 255.255.255.0 broadcast x.x.x.255 gateway x.x.x.1 network x.x.x.0
Add nameservers to /etc/resolv.conf and bring up the interfaces:
# ifup eth0 # ifup lo
See if you can install the sshd daemon:
# apt-get install ssh
If this works, you've got networking. You should also be able to ssh into the Debian host from the outside.