Re: [Xen-users] Convert physical server to VM

[Marc Patino Gómez <mpatino@xxxxxxxxxxxx>]

Hi,

remenber, there exist 2 kinds of virtualization in XEN:

- paravirtualization
- full virtualization

we are talking about "full virtualitzation" (unmodified guest) no?

In full virtualization you needs something thats seems a real disc, with 
MBR, partition table, partitions with corresponding filesystems... the 
only way that I know to copy all this is with dd command.
What version of Xen are you using? I don't have any file named 
domUloader.py :S
Regards,

Marc

Chiu, PCM (Peter) wrote:
> Thanks, Marc,
>
> This is different from what is described on the Xen V3.0 User's Manual Page 34,
> where it shows a selection of root file system files are copied.
>
> Probably there is where it gets wrong.
>
> On the other hand, some of our existing kits are having a root file system 
> being partitioned off a RAIDed storage, so the whole disk (/dev/sda) is in Terabyte large.
> I shall your method first, which I believe will also copy the boot block info.
> This process will take some time.
>
> Can I also check one thing with you.
> My current vm configuration file is a copy of an Suse 10.2 guest configuration.
> This contains the following bootloader info:
>
>   
>   bootloader = '/usr/lib/xen/boot/domUloader.py'
>   bootentry = 'hda1:/boot/vmlinuz-xen,/boot/initrd-xen'
>
> Bearing in mind, the guest Linux VM does not have /boot/vmlinuz-xen and 
> /boot/initrd-xen
> in its own /boot folder.  Shall I change them to:
>   kernel = "/boot/vmlinuz"
>   ramdisk = "/boot/initrd"
>
> to reflect the actual kernel and ramdisk residing on the guest /boot folder?
>
> Peter
>
>
> -----Original Message-----
> From: Marc Patino Gómez [mailto:mpatino@xxxxxxxxxxxx] 
> Sent: 23 August 2007 15:25
> To: Chiu, PCM (Peter)
> Cc: Simon Gao; xen-users@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [Xen-users] Convert physical server to VM
>
> Hi,
>
> the problem is that you only copy the filesystem with tar command. You must 
> copy the FULL disc, to do this follow use dd, as I post before
>
> dd if=/dev/hda | ssh root@xxxxxxxxxxxxxxxxx "/bin/dd of=/xen/images/myimage.img"
>
>
> so the process will be:
>
> 1- dd if=/dev/zero of=image.img bs=1M count=4096 (if you have a 4GB HD, if your 
> physical HD is 4GB)
>    remember, the image must be at least the same size than your original HD)
>
> 2- stop old box, and boot with a LiveCD
>
> 3- Copy the disc to your XEN server
>    dd if=/dev/hda | ssh root@xxxxxxxxxxxxxxxxx "/bin/dd 
> of=/xen/images/myimage.img"
>
>
> Good luck,
>
> Marc
>
> Chiu, PCM (Peter) wrote:
>   
> > Thanks, Marc, for your speedy response.
> >
> > I was hoping to set up a guest VM on existing Suse9/10 and Redhat4/5 systems.
> >
> > Still, I use tar to copy the whole of the root directory tree on a 
> > running Linux system into the loop mounted image.
> > Here are the steps I took:
> > dd if=/dev/zero of=image bs=1k seek=10240k count=1 mkfs -t ext3 image 
> > mount -o loop image /mnt/temp cd /mnt/temp ssh remote "tar -zaxHS -f - 
> > /" | tar -zxpf - cd umount /mnt/temp
> > I then use Yast2 xen to create a guest VM configuration and start it.  
> > But it fails with the "Boot loader didn't return any data" error.
> > I also tried to re-create a vm configuration file by copying a working 
> > Suse 10.2 one, but still hit the same fault.
> > So I suspect something is missing to make the above image to be bootable.
> >
> > Any idea?
> >
> > Peter
> > -----Original Message-----
> > From: Marc Patino Gómez [mailto:mpatino@xxxxxxxxxxxx]
> > Sent: 23 August 2007 14:24
> > To: Chiu, PCM (Peter)
> > Cc: Simon Gao; xen-users@xxxxxxxxxxxxxxxxxxx
> > Subject: Re: [Xen-users] Convert physical server to VM
> >
> >
> > Hi,
> >
> > Chiu, PCM (Peter) wrote:
> >   
> >     
> > > Hi, there,
> > >
> > > I am watching this thread with interest.
> > >
> > > Marc, can you repeat the actual steps you do to set up Linux guest 
> > > VMs, especially the ones using 2.4 kernels.
> > > I have tried similar steps you mentioned, apart from the cp -pr 
> > > /lib/modules into the guest OS disk, but when I start up the guest 
> > > VM, it complains
> > >   
> > >     
> > >       
> > If you are going to "full virtualitzed" a linux box you don't need to copy the 
> > kernel's modules, you will use the unmodified old OS kernel ones, and the old kernel (of 
> > course).
> >   
> >     
> > > "boot loader didn't return any data!"
> > >   
> > >     
> > >       
> > Have you copy the full HD? or only the partition?
> >   
> >     
> > > It looks like something is missing to turn the root copied file 
> > > system to be bootable as a guest VM.
> > > Thanks.
> > >
> > > Peter
> > >   
> > >     
> > >       
> > Good luck Peter,
> >
> > Marc
> >   
> >     
> > > -----Original Message-----
> > > From: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
> > > [mailto:xen-users-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of Marc 
> > > Patino Gómez
> > > Sent: 23 August 2007 12:05
> > > To: Simon Gao
> > > Cc: xen-users@xxxxxxxxxxxxxxxxxxx
> > > Subject: Re: [Xen-users] Convert physical server to VM
> > >
> > > Hi,
> > >
> > > rsync works great on production enviroments, I had paravirtualized some servers 
> > > with these method:
> > >
> > > rsync -ave ssh --exclude=/proc --exclude=/sys --exclude=/dev (if you 
> > > are using udev) root@runingserver:/  /mnt/newserverimage/
> > > after this:
> > >
> > > mkdir /mnt/newserverimages/proc
> > >
> > > mkdir /mnt/newserverimages/sys
> > >
> > > mkdir /mnt/newserverimages/dev
> > >
> > > review your fstab, and copy the kernel modules:
> > >
> > > cp -pr /lib/modules/2.6.16-xenU /mnt/newserverimages/lib/modules/
> > >
> > > more or less .... this is the way
> > >
> > > Also I have full virtualitzed some old GNU/Linux boxes with kernels 2.4, I used 
> > > GNU/Linux live CD on the old box and dd utility:
> > >
> > >
> > > dd if=/dev/hda | ssh root@xxxxxxxxxxxxxxxxx "/bin/dd 
> > > of=/dev/vg00/newvserver"
> > > I hope it will be helpfull
> > >
> > >
> > > Marc
> > >
> > > Simon Gao wrote:
> > >   
> > >     
> > >       
> > > > Hi,
> > > >
> > > > Anyone has any suggestions on programs, utility or instructions on 
> > > > how to convert a physical server to domU VM?
> > > > Thanks,
> > > >
> > > > Simon
> > > >
> > > > _______________________________________________
> > > > Xen-users mailing list
> > > > Xen-users@xxxxxxxxxxxxxxxxxxx
> > > > http://lists.xensource.com/xen-users
> > > >   
> > > >     
> > > >       
> > > >         
> > > _______________________________________________
> > > Xen-users mailing list
> > > Xen-users@xxxxxxxxxxxxxxxxxxx
> > > http://lists.xensource.com/xen-users
> > >   
> > >     
> > >       
> >   
> >     
>   

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