If running XenServer on a RAID array with writeback (controller cache) enabled and no battery backup, don’t lose power. If you do, you will discover the state.db is corrupt and XAPI fails to start. Everything is down, Dom0 lost it’s network config, you’re screwed. Maybe. This tutorial assumes you’ve got a metadata backup, all your […]
On a new XenServer deployment EXT storage is default. Although EXT is nice (ability to manipulate raw VHD files and use sparse storage), LVM is faster and more stable. Here is how to switch between storage modes (be sure to back up all data first, as this will wipe everything in the repo): Use ‘xe […]
Since XenServer 6.1 (XCP 1.6) there is a new feature that allows you to lock VIF to specific MAC and IP addresses. This is nice (and also very buggy!), but it doesn’t provide any security other than keeping VMs from stealing each others IPs. A better solution should allow to (optionally) isolate traffic between groups […]
Source is now in github, please help me make it better! If you just want a 32-bit binary (to run on Dom0), download it from here instead. With the help of Ben Booth’s Xen::API (Perl module) I put together a VM migration script to export a VM directly to another host with no intermediary file. […]
On multiple XenServer 5.x setups I’ve been experiencing dropped packets evident as light to medium packet loss on a busy DomU. It only affects heavy network loads on DomU’s and not Dom0. It also doesn’t seem to care about what OS is running; I’m seeing it in Debian, CentOS, and Windows. Since I manage streaming […]
Convert a XenServer HVM domain to PV (paravirtual) and back again with this simple script.
With SMP (multi-CPU) VM’s on Xen or XenServer running Debian Lenny you need to add the following kernel options if you’re getting soft lockups: clocksource=pit nohz=off
Twice now, I have had the (dis)pleasure of expanding our local storage on a couple of XenServer boxes. In a nutshell, here is how it works: 1. Expand physical disk (add more RAID members, ect). Use the procedure specific to your RAID card. 2. Use fdisk to expand the partition your Local Storage resides on: […]