Comments on XEN On An Ubuntu Hardy Heron (8.04) Server System (amd64) - High Performance

Hello,

Thanks for this great article, it's simple and efficient but I have some corrections and advices.

I would have done the:

# chroot /mnt /bin/bash

After these 4 commands (so I don't need to open an another terminal:

# cp /etc/resolv.conf /mnt/etc/resolv.conf

# cp /etc/network/interface /mnt/network/interface

# cp /etc/apt/source.list /mnt/etc/apt/sources.list

# cp -R /lib/modules/2.6.24-17-xen/* /mnt/lib/modules/2.6.24-17-xen/

Also, there are some typos (/etc/network/interface should be /etc/network/interfaces with a final s, /etc/apt/source.list should be /etc/network/sourceS.list)

The commands I typed looked like this:

# cp /etc/resolv.conf /mnt/etc
# cp /etc/network/interfaces /mnt/etc/network
# cp /etc/apt/sources.list /mnt/etc/apt

Also to copy the modules I used:

# mkdir /mnt/lib/modules/`uname -r`
# cp -R /lib/modules/`uname -r`/* /mnt/lib/modules/`uname -r`/

 Instead of :

# cp -R /lib/modules/2.6.24-17-xen/* /mnt/lib/modules/2.6.24-17-xen/

 I'm wondering if after the chroot and apt-get update, when we are doing "apt-get upgrade" we aren't supposed to do an "apt-get dist-upgrade" , but the result is seems to be the same.

Finally, for the root filesystem of my vm, I haven't used a physical partition, I've used a file on my dom0's filesystem.

To do so, I have executed the following commands:

# mkdir /home/xen ; cd /home/xen

# dd if=/dev/zero of=hardyvm.root bs=10M count=100
# mkfs.ext3 hardyvm.root
# mount -o loop hardyvm.root /mnt/

This dd command creates a 1Gig file with no data.

Then in "/etc/xen/domu1.cfg" I have that line:

disk        = ['tap:aio:/home/xen/hardyvm.root,hda1,w',]

 Note the 'tap:aio:/home/xen/hardyvm.root' instead of 'phy:/dev/sda2,hda1'

Otherwise , this tutorial is great, simple and straightforward !

Thank you very much !

Hello,

 Nice to see corrections from you.

 But still think, one should use "phy:" than "tap:"  as writing on physical disk is quite faster than writing on image-file. I already have experienced the same many a times on production environments.

 Thanks.

I dont have an AMD64 based computer.. what am I to do?

I get a series of error even before that!

like is xen running?

/mnt is empty?!

xen is not in my menu.lst file and is not loading at the boot up?!

I manually downloaded xen3.3.0.tar.gz and expanded it in to /xen3xyz  folder but i get a bunch of errors when i do ./install.sh!?

i moved it around still the same error...

thanks..

 

Hi, I followed the howto, I was able to successfully start the domu1 virtual machine but I ran into problems.

First, networking doesnt work :( I can see eth0 but it has no ip address.

Second, when I type df -h I dont see /dev/hda1. Is that normal?

I tried Falko howto (with image file), networking was working and I could see the "partition" doing df -h but I would prefer to write directly on a partition instead of an image file. Did some quick benchmark with his method, drive performance using an image file was around 50% of the native drive performance which is quite bad....

 Also is there anything special I need to put in the domain config file with a dual cpu machine? I have dual (2x)  xeon 5140 processor (dual core) with HT enabled. How many VCPU i have available? 4, 8?

thanks for your help!

Marc

Hi Marc,

Problem: First, networking doesn't work :( I can see eth0 but it has no ip address.

Ans:  You need to asign IP to domU either in /etc/network/interfaces or through /etc/xen/domu1.cfg file.

 

Problem: Second, when I type df -h I dont see /dev/hda1. Is that normal?

Ans: Yes it's normal. This is because we have define /dev/hda1 in /etc/fstab file of domU(s). You can spesify /dev/sda1 as well. But don't forget to change /etc/xen/domu1.cfg file accordingly.

-- Hope this clears your doubts.

 

This is really a great tutorial.

I do however have the following questions:

1. I have 5 public addresses for the physical server and I would like to use one of them for domu1 and another one for domu2. Is this possible or should I other IPs
2. how can I install on domu2 another OS like windows or any non linux OS

Thank you

This posting deals with utilizing same image device for loading HVM and PV Ubuntu Hardy DomUs at Ubuntu Hardy Dom0 (2.6.24-21-xen #1 SMP Mon Aug 25 18:56:44 UTC 2008 x86_64 GNU/Linux). This approach allows to avoid traditional "debootstrap" procedure as well as taking a long time "apt-get install ubuntu_desktop", what is, actually, 400 MB download. It also provides a workaround to get Gnome Desktop working stable at Ubuntu PV DomU no matter on Xen Release (>=3.1.2) and OS (Solaris,Linux) running at Dom0. Install Ubuntu Hardy HVM DomU via hvm-profile.

http://librenix.com/?inode=12795

Would be very interesting if there were a tutorial on how to install a Windows Guest on Ubuntu Xen!