Xen for Debian ============== Config behaviour ---------------- The Debian packages changes the behaviour of some config options. The options "kernel", "initrd" and "loader" searches in the Xen private boot directory (/usr/lib/xen-$version/boot) first. "bootloader" and "device_model" also searches the Xen private bin directory (/usr/lib/xen-$version/bin). This means that the following entries will properly find anything: loader = 'hvmloader' bootloader = 'pygrub' Network setup ------------- The Debian package of Xen don't change the network setup in any way. This differs from the upstream version, which overwrites the main network card (eth0) with a bridge setup and may break the network at this point.. To setup a bridge please follow the instructions in the manpage for bridge-utils-interfaces(5). You can also change the /etc/xen/xend-config.sxp file and re-enable the Xen included network setup by adding (network-script network-bridge) to the file. But please note that this may or may not work. Loop devices ------------ If you plan hosting virtual domains with file backed block devices (ie. the ones xen-tools creates by default) be careful about two issues: 1. Maximum number of loop devices By default the loop driver supports a maximum of 8 loop devices. Of course since every Xen domain uses at least two (one for the data and one for the swap) this number is absolutely insufficient. You should increase it by adding a file named local-loop in /etc/modprobe.d containing the string "options loop max_loop=128", if the loop driver is compiled as a module, or by appending the string max_loop=128 to your kernel parameters if the driver is in-kernel. Of course you can increase or decrease the number 128 as you see fit. 2. Driver loading (only if loop is compiled as a module) Normally the loop driver gets loaded when the first loop device is accessed. When using udev, though, the loop devices get created only after the driver gets loaded. This means that Xen will fail if the loop driver is not already loaded when it tries to start a file-backed virtual domain. To fix this just add "loop" in your /etc/modules file, thus forcing it to be loaded at boot time.