Upgrade_Xen_on_dom0

= dist-upgrade dom0 =

cat /etc/apt/sources.list deb http://ftp.ie.debian.org/debian/ stable main deb-src http://ftp.ie.debian.org/debian/ stable main

apt-get dist-upgrade

The upgrade itself went very well. There were the usual prompts and questions about whether to keep default configs, which I accepted. Make sure you have sufficient room on /boot also for the new kernels! If not, then apt-get remove some of the older unused kernels.

What did the dist-upgrade install:

Latest Kernel and Xen Kernel: linux-image-2.6.26-1-xen-686
Kept Xen3.0!: xen-hypervisor-3.0.3-1-i386-pae
Kept xen-utils-3.0.3-1.

I checked the grub entry after the dist-upgrade ( vi /boot/grub/menu.lst ). As I had everything with grub and the defaults sorted before as in dom0_mem_Automatic_setting.

Default Xen Kernel Grub Entry after dist-upgrade

title Xen 3.0.3-1-i386-pae / Debian GNU/Linux, kernel 2.6.26-1-xen-686 root (hd0,0) kernel /xen-3.0.3-1-i386-pae.gz dom0_mem=128000 module /vmlinuz-2.6.26-1-xen-686 root=/dev/mapper/hexvg-root ro acpi=off console=tty0 module /initrd.img-2.6.26-1-xen-686

Unfortunately, the server did not come up after reboot I added “noreboot” to the following line to prevent the automatic reboot (as it was rebooting continuously trying to boot the kernel): kernel /xen-3.0.3-1-i386-pae.gz dom0_mem=128000 noreboot

Luckily, there was someone to hand (moonpie) who rebooted the server, chose the old Xen kernel entry in the Grub Boot list: “title Xen 3.0.3-1-i386-pae / Debian GNU/Linux, kernel 2.6.18-6-xen-686”

= Upgrade to Xen3.2 to get dom0 to boot = So with “kernel 2.6.26-1-xen-686” and “Xen 3.0.3-1-i386-pae” the server did not want to start, nor did it give a reason.

I decided to upgrade to Xen3.2. dpkg -l | grep hyper #This showed I had the pae version ( xen-hypervisor-3.0.3-1-i386-pae ) apt-cache search xen | grep hyper #This showed both xen-hypervisor-3.2-1-i386 and xen-hypervisor-3.2-1-i386-nonpae apt-get install xen-hypervisor-3.2-1-i386 #This pulled down all other packages it needed

After installing, grub kicked in and updated the menu.lst. The boot list was as follows: title Xen 3.0.3-1-i386-pae / Debian GNU/Linux, kernel 2.6.26-1-xen-686 root (hd0,0) kernel /xen-3.0.3-1-i386-pae.gz dom0_mem=128000 module /vmlinuz-2.6.26-1-xen-686 root=/dev/mapper/hexvg-root ro acpi=off console=tty0 module /initrd.img-2.6.26-1-xen-686

title Xen 3.2-1-i386 / Debian GNU/Linux, kernel 2.6.26-1-xen-686 root (hd0,0) kernel /xen-3.2-1-i386.gz dom0_mem=128000 noreboot module /vmlinuz-2.6.26-1-xen-686 root=/dev/mapper/hexvg-root ro acpi=off console=tty0 module /initrd.img-2.6.26-1-xen-686

title Xen 3.0.3-1-i386-pae / Debian GNU/Linux, kernel 2.6.18-6-xen-686 root (hd0,0) kernel /xen-3.0.3-1-i386-pae.gz dom0_mem=128000 module /vmlinuz-2.6.18-6-xen-686 root=/dev/mapper/hexvg-root ro acpi=off console=tty0 module /initrd.img-2.6.18-6-xen-686

title Xen 3.2-1-i386 / Debian GNU/Linux, kernel 2.6.18-6-xen-686 root (hd0,0) kernel /xen-3.2-1-i386.gz dom0_mem=128000 module /vmlinuz-2.6.18-6-xen-686 root=/dev/mapper/hexvg-root ro acpi=off console=tty0 module /initrd.img-2.6.18-6-xen-686

Note: Xen 3.2-1-i386 was #2

Option 1: apt-get remove xen-hypervisor-3.0.3-1-i386-pae
Option 2:

vi /boot/grub/menu.lst #default 0 default 1 #Note. It starts at 0, so 1 is the second on the list (as shown above). This should be fine. Running a “update grub” will not affect this setting.

Reboot and see.

= Update domU configs = While dist-upgrading dom0, I didn't bother powering off the domU's. I also simply done a reboot of dom0 after the dist-upgrade. Anyways, to overcome the issues outlined in Upgrade_domU_to_Lenny I wanted domU's to use the latest kernel. vi /etc/xen/auto/hex-vm06.cfg #replace .18 kernel with .26.

Problems with domU and Xen3.2

xm create hex-vm06 -c (-c = console) The console froze.
trying to ssh to the server resulted in “stdin: is not a tty”

After some googling, this seemed to be a common problem! Specifically it was due to udev not been installed on domU (which is default for xen-tools and debootstrap).

After much more googling and attempts the following was used:

vi /etc/xen/hex-vm06.cfg extra = 'xencons=tty'

mount /dev/mapper/hexvg-hex–vm06–disk /mnt/ chroot /mnt/ apt-get install udev #will see the following, but can ignore: Setting up udev (0.105-4) … /sys/class/net/ is not available, persistent interface names not saved. A chroot environment has been detected, udev not started.

vi /etc/udev/persistent-net-generator.rules #see below for explanation. #change: SUBSYSTEMS==“xen”, \

ENV{COMMENT}="Xen virtual device"

#to: SUBSYSTEMS==“xen”, \

ENV{COMMENT}="Xen virtual device", GOTO="persistent_net_generator_end"

exit #exit the chroot

cp -a /lib/modules/2.6.26-1-xen-686/ /mnt/lib/modules/ umount /mnt/

As for “/etc/udev/persistent-net-generator.rules”. Well, with udev now installed, I hit a previous problem I had identified here A while ago, I received a kind email from a Timo Stripf, who had another solution, instead of hardcoding a mac address into each xen domU config.

I've found a different solution to fix the udev problem. You can modify the udev rules to ignore xen network interfaces.

In /etc/udev/persistent-net-generator.rules simple add a GOTO directive behind SUBSYSTEM=“xen”:

SUBSYSTEMS==“xen”, \

ENV{COMMENT}="Xen virtual device", GOTO="persistent_net_generator_end"

Best regards Timo Stripf Timo Stripf

And it worked a treat. Several poweroff's and xm shutdowns, eth0 was not incremented. This was extremely useful on one of my xen servers which I use xen-tools to create vms quickly.

Linux Server Details

Table of Contents

Upgrade_Xen_on_dom0

Default Xen Kernel Grub Entry after dist-upgrade

Problems with domU and Xen3.2

More problems with domU and Xen3.2

Problem with time

Solution to time