Xen

Install Xen Server 5.5 on Hetzner Server

You need an additional computer on which the installation files are stored. They are downloaded then via http.

Prepare Webserver

I use as webserver a FreeBSD:

wget http://downloadns.citrix.com.edgesuite.net/akdlm/4210/FREE_XenServer-5.5.0-install-cd.iso
mdconfig -a -t vnode -f FREE_XenServer-5.5.0-install-cd.iso -u 0
mount -t cd9660 /dev/md0 /mnt
mkdir /usr/local/www/apache22/data/xenserver
cp -a /mnt/* /usr/local/www/apache22/data/xenserver
umount mnt
mdconfig -d -u 0

Create the unattended installation file, you can use the following tool to do this [1] and save it as xenserver.xml on the webserver.

<?xml version="1.0" standalone="no"?>
<!--
************************************************************
*   XML answer file for unattend Xenserver installation     
* created by XenServer PXE Install Tool - (c) Thomas Krampe 
*                                                           
*  BE CAREFUL IF YOU CHANGE SOMETHING MANUALLY IN THS FILE  
*                                                           
************************************************************
-->
<installation mode="fresh" srtype="lvm">
   <bootloader>grub</bootloader>
   <primary-disk gueststorage="yes">sda</primary-disk>
   <keymap>de</keymap>
   <hostname>xen</hostname>
   <root-password>_password_</root-password>
   <source type ="url">http://_IP_WEBSERVER_/xenserver</source>
   <!-- No Post install scripts configured -->
   <admin-interface name="eth0" proto="static">
      <ip>_IP_</ip>
      <subnet-mask>255.255.255.192</subnet-mask>
      <gateway>_GATEWAY_</gateway>
   </admin-interface>
   <nameserver>213.133.99.99</nameserver>
   <nameserver>213.133.100.100</nameserver>
   <timezone>Europe/Berlin</timezone>
   <time-config-method>ntp</time-config-method>
   <ntp-servers>ntp</ntp-servers>
   <ntpservers>83.246.120.75</ntpservers>
   <ntpservers>213.9.73.106</ntpservers>
   <ntpservers>188.40.34.195</ntpservers>
</installation>

Installation of Xen

Install a standard linux on it like Debian. Login and copy the following files to /boot:

cd /boot
wget http://_IP_/xenserver/boot/vmlinuz
wget http://_IP_/xenserver/boot/xen.gz
wget http://_IP_/xenserver/install.img

Now we great the grub entry in /boot/grub/menu.lst

default 2

title Install Xenserver
root (hd0,1)
kernel /xen.gz dom0_mem=752M acpi=off nosmp noapic noirqbalance
module /vmlinuz answerfile=http://_IP_/xenserver/xenserver.xml install
module /install.img

Now reboot and check on the webserver if it loads the files.

Use Raid1 on the XEN Server

Copy the partition table from disk 1 to disk 2:

dd if=/dev/sda of=/dev/sdb bs=512 count=1

Create raid partitions on second hard disk:

echo -e "\nt\n1\nfd\nt\n3\nfd\nw\nx" | fdisk /dev/sdb

I got an warning message here:

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.

so I rebooted the system.

Create raid devices:

[ -e /dev/md0 ] || mknod /dev/md0 b 9 0
[ -e /dev/md1 ] || mknod /dev/md1 b 9 1

Startup the degraded RAID devices

mdadm --create /dev/md0 --level=1 --raid-devices=2 missing /dev/sdb1
mdadm --create /dev/md1 --level=1 --raid-devices=2 missing /dev/sdb3

Create the volume:

pvcreate /dev/md1
volume_group=`vgscan | grep VG | awk -F \" '{print $2}'`
vgextend $volume_group /dev/md1
pvmove /dev/sda3 /dev/md1
# If this is a fresh install, then there won't be any data to move
vgreduce $volume_group /dev/sda3

Now we’re ready to copy the filesystem over to the RAID device /dev/md0

mkfs.ext3 /dev/md0
cd / && mount /dev/md0 /mnt && rsync -a --progress --exclude=/sys --exclude=/proc --exclude=/dev/shm --exclude=/dev/pts / /mnt
mkdir /mnt/sys
mkdir /mnt/proc

sed -r -i 's,LABEL=root-\w+ ,/dev/md0 ,g' /mnt/etc/fstab

Now let’s setup initrd

mkdir /root/initrd && cd /root/initrd
zcat /boot/initrd-`uname -r`.img | cpio -i && \
cp /lib/modules/`uname -r`/kernel/drivers/md/raid1.ko lib

Now we have to edit the init file:

q="echo Waiting for driver initialization."
sed -r -i "s,^${q}$,\n\necho Loading raid1.ko module\ninsmod /lib/raid1.ko\n${q}\n,g" init
q="resume /var/swap/swap.001"
sed -r -i "s,^${q}$,${q}\necho Running raidautorun\nraidautorun /dev/md0\nraidautorun /dev/md1,g" init
r=`grep mkroot /root/initrd/init`
sed -r -i "s|^${r}$|${r/sda1/md0}|g" init

Now we’ll copy the initial ramdisk to the /boot on the new RAID

find . -print | cpio -o -c | gzip -c > /boot/initrd-`uname -r`.img
sed -r -i 's,LABEL=root-\w+ ,/dev/md0 ,g' /mnt/etc/fstab
sed -r -i 's,LABEL=root-\w+ ,/dev/md0 ,g' /etc/fstab

And setup the boot loader

sed -r -i 's,root=LABEL=root-\w+ ,root=/dev/md0 ,g' /mnt/boot/grub/grub.conf
sed -r -i 's,root=LABEL=root-\w+ ,root=/dev/md0 ,g' /boot/grub/grub.conf
grub-install /dev/sdb

Unmount /dev/md0, sync, and reboot

cd ; umount /mnt || umount /dev/md0
sync
reboot

First we tag the partitions as type Linux raid, then we have to add /dev/sda to the RAID.

echo -e "\nt\n1\nfd\nt\n3\nfd\nw\nx" | fdisk /dev/sda
mdadm -a /dev/md0 /dev/sda1
mdadm -a /dev/md1 /dev/sda3

Now it restores the raid, that can take some time, you can see it with:

cat /proc/mdstat

Add local ISO to Xen

Create a directory with:

mkdir -p /var/opt/xen/iso_import

Create now a ISO storage repository:

xe sr-create name-label=MyISORepository type=iso device-config:location=/var/opt/xen/iso_import/ device-config:legacy_mode=true content-type=iso

Now copy for files to

/var/opt/xen/iso_import/

Create Volume for ISOs on LVM

To find the volume ID:

vgscan

Create new LVM to hold the ISOs, in this case 12GB:

lvcreate -L 12G -n ISO VG_XenStorage-fb805573-ae34-9739-c362-521d364cc04b

Create file system:

mkfs.ext3 /dev/VG_XenStorage-fb805573-ae34-9739-c362-521d364cc04b/ISO

Adapt /etc/exports:

mkdir /ISO
echo "/ISO *(rw,no_root_squash,sync)" >> /etc/exports

Start NFS and portmapper:

chkconfig --level 345 nfs on
chkconfig --level 345 portmap on
service nfs start
service portmap start 

Enable mount at boot:

lvchange -a y /dev/VG_XenStorage-fb805573-ae34-9739-c362-521d364cc04b/ISO
mount /dev/VG_XenStorage-fb805573-ae34-9739-c362-521d364cc04b/ISO /ISO

Add ISO library to XenCenter: Click 'New Storage Repository' and select 'NFS ISO'. As mount point use localhost:/ISO.