[Xen-users] Re: Re: How to Backup and Restore MBR within Logical Volumes?

["Mr. Teo En Ming (Zhang Enming)" <space.time.universe@xxxxxxxxx>]

On Fri, Nov 13, 2009 at 9:17 PM, Dustin Henning <Dustin.Henning@xxxxxxxxxxx> wrote:

       As you are running Windows, I will assume that you are using HVM,
and therefore that /dev/virtualmachines/windows7-x64 is a hard disk image.
As such, the command you listed will back up the MBR, including the
partition table.  That isn't to say that Windows 7 doesn't have additional
boot information outside of the MBR, but that information would be included
in a file system backup.  Wikipedia has the structure of the MBR in a table
at http://en.wikipedia.org/wiki/Master_boot_record.  On that note, I often
use bs=446 when I want the MBR without the partition table, but if you are
backing up the partition as opposed to the file structure, then you might as
well keep the partition table (or even just back up the image).
       Dustin

From: fedora-xen-bounces@xxxxxxxxxx [mailto:fedora-xen-bounces@xxxxxxxxxx]
On Behalf Of Mr. Teo En Ming (Zhang Enming)
Sent: Thursday, November 12, 2009 04:45
To: Geert Janssens
Cc: Community assistance, encouragement, and advice for using Fedora.;
xen-users@xxxxxxxxxxxxxxxxxxx; Fedora Xen
Subject: [Fedora-xen] Re: [Xen-users] How to Backup and Restore MBR within
Logical Volumes?

> dd if=/dev/virtualmachines/windows7-x64 of=mbr.w7-x64 bs=512 count=1

I think if you do this, you are only backing up the first 512 bytes of the
logical volume, not the MBR.

Someone correct me if I am wrong.

--
Mr. Teo En Ming (Zhang Enming) Dip(Mechatronics) BEng(Hons)(Mechanical
Engineering)
Alma Maters:
(1) Singapore Polytechnic
(2) National University of Singapore
My Primary Blog: http://teo-en-ming-aka-zhang-enming.blogspot.com
My Secondary Blog: http://enmingteo.wordpress.com
My Youtube videos: http://www.youtube.com/user/enmingteo
Email: space.time.universe@xxxxxxxxx
Mobile Phone (Starhub Prepaid): +65-8369-2618
Street: Bedok Reservoir Road
Country: Singapore
On Thu, Nov 12, 2009 at 9:36 AM, Geert Janssens <info@xxxxxxxxxxxx> wrote:
On Thursday 12 November 2009, Mr. Teo En Ming (Zhang Enming) wrote:
> Hi All,
>
> I have several Xen virtual machines within logical volumes using LVM2. I
> did not use disk images for performance reasons.
>
> Conventionally, if I want to clone my virtual machines, I have to dd the
LV
> to an image file. But this consumes a lot of time and harddisk space.
>
> So, instead of doing that, I want to use losetup and kpartx with my
logical
> volumes, which contain operating systems of virtual machines.
>
> I can backup the filesystems of a virtual machine in this way:
>
> # losetup /dev/loop1 /dev/virtualmachines/windows7-x64
>
Are you sure you need to call losetup first ?

I remember I used kpartx directly on the lvm containing my vbd.

Also, I think you can treat the lvm based vbd as a real disk.

So
dd if=/dev/virtualmachines/windows7-x64 of=mbr.w7-x64 bs=512 count=1

should backup your mbr.

Anyone correct me if I'm wrong please.

Geert

--
Kobalt W.I.T.
Web & Information Technology
Brusselsesteenweg 152
1850 Grimbergen

Tel  : +32 479 339 655
Email: info@xxxxxxxxxxxx


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Hi Dustin,

The MBR backup guide that I was following is this one:

Article: MBR tricks with Linux

Link: http://www.tuxation.com/mbr-tricks-with-linux.html

Here is the final version of my data restore script. Could you check if there are mistakes in it?

<SCRIPT>
#!/bin/sh

###############################################################################################################
###############################################################################################################
# Script to Restore Xen Host/Dom0 and all DomUs which are using Logical Volumes as Virtual Hard Disks
###############################################################################################################
###############################################################################################################

# Written by:
 
# Mr. Teo En Ming (Zhang Enming) Dip(Mechatronics) BEng(Hons)(Mechanical Engineering)
# Alma Maters:
# (1) Singapore Polytechnic
# (2) National University of Singapore
# Primary Blog: http://teo-en-ming-aka-zhang-enming.blogspot.com
# Secondary Blog: http://enmingteo.wordpress.com
# Youtube Videos: http://www.youtube.com/user/enmingteo
# Xen Tutorials and Video Demos: http://www.xen.org/support/tutorial.html
# Email: space.time.universe@xxxxxxxxx
# MSN: teoenming@xxxxxxxxxxx
# Mobile Phone (Starhub Prepaid): +65-8369-2618
# Street: Bedok Reservoir Road
# Country: Singapore

# First written: 13 November 2009 Friday 6:49 P.M. Singapore time
# Last updated: 13 November 2009 Friday 8:25 P.M. Singapore time
# Last updated: 13 November 2009 Friday 8:59 P.M. Singapore time
# Last updated: 13 November 2009 Friday 9:40 P.M. Singapore time

# REFERNCE: "Geek Sheet: Bare-metal backup and recovery", May 7th, 2008, Jason Perlow
# URL: http://blogs.zdnet.com/BTL/?p=8759

# Usage Instructions:

# Boot up your desktop/server with System Rescue CD version 1.3.2 for i386/amd64. 
# Then execute this restore script. You need to adapt this script to work for your environment.
# Download System Rescue CD from http://www.sysresccd.org/Main_Page

# No. of QC Checks Performed on this restore script: 1 

###############################################################################################################
# Declare Variables
###############################################################################################################

HARDDISK=/dev/sda
SOURCE=/media/hitachi/test

###############################################################################################################
###############################################################################################################
# Restoring Xen Host/Dom0
###############################################################################################################
###############################################################################################################

# Restore the Master Boot Record
dd if=$SOURCE/f11-xen-dom0-sda.mbr of=$HARDDISK bs=512 count=1

# Restore the Partition Geometry
sfdisk $HARDDISK < $SOURCE/f11-xen-dom0-partition-geometry-sda.sfdisk

# Re-create the LVM2 PV containing the host operating system/dom0
pvcreate --uuid ??? /dev/sda2

# Re-create the LVM2 PV containing all the virtual machines
pvcreate --uuid ??? /dev/sda3

# Restore the LVM2 metadata for the volume group containing the host operating system/dom0
vgcfgrestore --file $SOURCE/vg_fedora11_host-vgcfg.lvm2.metadata vg_fedora11_host

# Restore the LVM2 metadata for the volume group containing all the virtual machines
vgcfgrestore --file $SOURCE/virtualmachines-vgcfg.lvm2.metadata virtualmachines

# Activate all the volume groups
vgchange -ay

# Restore all filesystems for the host operating system/dom0
fsarchiver restfs -v $SOURCE/f11-xen-dom0-filesystems.fsa id=0,dest=/dev/sda1 \
id=1,dest=/dev/vg_fedora11_host/lv_home \
id=2,dest=/dev/vg_fedora11_host/lv_root \
id=3,dest=/dev/vg_fedora11_host/lv_var

# Re-create the swap partition
mkswap /dev/vg_fedora11_host/lv_swap

###############################################################################################################
###############################################################################################################
# Restoring Xen-based Virtual Machines/DomUs/Guest Operating Systems/VMs
###############################################################################################################
###############################################################################################################

### NOTE: Check for swap partitions in each virtual machine and do a mkswap.

# VM 1: Fedora 11 x86_64 PV domU (MPICH2 Virtual Supercomputer Center)
###############################################################################################################

zcat $SOURCE/virtualmachines-f11-pv-hpc-node0001.img.gz | dd of=/dev/virtualmachines/f11-pv-hpc-node0001

# VM 2: Fedora 11 x86_64 PV domU (MPICH2 Virtual Supercomputer Center)
###############################################################################################################

zcat $SOURCE/virtualmachines-f11-pv-hpc-node0002.img.gz | dd of=/dev/virtualmachines/f11-pv-hpc-node0002

# VM 3: Fedora 11 x86_64 PV domU (MPICH2 Virtual Supercomputer Center)
###############################################################################################################

zcat $SOURCE/virtualmachines-f11-pv-hpc-node0003.img.gz | dd of=/dev/virtualmachines/f11-pv-hpc-node0003

# VM 4: Fedora 11 x86_64 PV domU (MPICH2 Virtual Supercomputer Center)
###############################################################################################################

zcat $SOURCE/virtualmachines-f11-pv-hpc-node0004.img.gz | dd of=/dev/virtualmachines/f11-pv-hpc-node0004

# VM 5: Fedora 11 x86_64 PV domU (MPICH2 Virtual Supercomputer Center)
###############################################################################################################

zcat $SOURCE/virtualmachines-f11-pv-hpc-node0005.img.gz | dd of=/dev/virtualmachines/f11-pv-hpc-node0005

# VM 6: Fedora 11 x86_64 PV domU (MPICH2 Virtual Supercomputer Center)
###############################################################################################################

zcat $SOURCE/virtualmachines-f11-pv-hpc-node0006.img.gz | dd of=/dev/virtualmachines/f11-pv-hpc-node0006

# VM 7: Fedora 11 x86_64 PV domU (MPICH2 Virtual Supercomputer Center)
###############################################################################################################

zcat $SOURCE/virtualmachines-f11-pv-hpc-node0007.img.gz | dd of=/dev/virtualmachines/f11-pv-hpc-node0007

# VM 8: Fedora 11 x86_64 PV domU (MPICH2 Virtual Supercomputer Center)
###############################################################################################################

zcat $SOURCE/virtualmachines-f11-pv-hpc-node0008.img.gz | dd of=/dev/virtualmachines/f11-pv-hpc-node0008

# VM 9: FreeBSD 8.0 RC2 UNIX amd64 HVM domU
###############################################################################################################

zcat $SOURCE/virtualmachines-freebsd.img.gz | dd of=/dev/virtualmachines/freebsd

# VM 10: OpenSolaris 2009.06 UNIX amd64 PV domU
###############################################################################################################

zcat $SOURCE/virtualmachines-opensolaris.img.gz | dd of=/dev/virtualmachines/opensolaris

# VM 11: Rocks 5.1 x86_64 HPC Compute Cluster HVM domU (based on CentOS 5.2)
###############################################################################################################

# Add partition mappings in /dev/mapper
kpartx -av /dev/virtualmachines/rocks0001

# Restore MBR
dd if=$SOURCE/virtualmachines-rocks0001.mbr of=/dev/virtualmachines/rocks0001 bs=512 count=1

# Restore partition geometry
sfdisk /dev/virtualmachines/rocks0001 < $SOURCE/virtualmachines-rocks0001.sfdisk

# Restore all filesystems
partimage -e -b restore /dev/mapper/virtualmachines-rocks0001p1 $SOURCE/virtualmachines-rocks0001p1.img.000

partimage -e -b restore /dev/mapper/virtualmachines-rocks0001p2 $SOURCE/virtualmachines-rocks0001p2.img.000

partimage -e -b restore /dev/mapper/virtualmachines-rocks0001p5 $SOURCE/virtualmachines-rocks0001p5.img.000

# Re-create swap
mkswap /dev/mapper/virtualmachines-rocks0001p3

# Delete partition mappings in /dev/mapper
kpartx -dv /dev/virtualmachines/rocks0001

# VM 12: Rocks 5.1 x86_64 HPC Compute Cluster HVM domU (based on CentOS 5.2)
###############################################################################################################

# Add partition mappings in /dev/mapper
kpartx -av /dev/virtualmachines/rocks0002

# Restore MBR
dd if=$SOURCE/virtualmachines-rocks0002.mbr of=/dev/virtualmachines/rocks0002 bs=512 count=1

# Restore partition geometry
sfdisk /dev/virtualmachines/rocks0002 < $SOURCE/virtualmachines-rocks0002.sfdisk

# Restore all filesystems
partimage -e -b restore /dev/mapper/virtualmachines-rocks0002p1 $SOURCE/virtualmachines-rocks0002p1.img.000

partimage -e -b restore /dev/mapper/virtualmachines-rocks0002p2 $SOURCE/virtualmachines-rocks0002p2.img.000

partimage -e -b restore /dev/mapper/virtualmachines-rocks0002p5 $SOURCE/virtualmachines-rocks0002p5.img.000

# Re-create swap
mkswap /dev/mapper/virtualmachines-rocks0002p3

# Delete partition mappings in /dev/mapper
kpartx -dv /dev/virtualmachines/rocks0002

# VM 13: Rocks 5.1 x86_64 HPC Compute Cluster HVM domU (based on CentOS 5.2)
###############################################################################################################

# Add partition mappings in /dev/mapper
kpartx -av /dev/virtualmachines/rocks0003

# Restore MBR
dd if=$SOURCE/virtualmachines-rocks0003.mbr of=/dev/virtualmachines/rocks0003 bs=512 count=1

# Restore partition geometry
sfdisk /dev/virtualmachines/rocks0003 < $SOURCE/virtualmachines-rocks0003.sfdisk

# Restore all filesystems
partimage -e -b restore /dev/mapper/virtualmachines-rocks0003p1 $SOURCE/virtualmachines-rocks0003p1.img.000

partimage -e -b restore /dev/mapper/virtualmachines-rocks0003p2 $SOURCE/virtualmachines-rocks0003p2.img.000

partimage -e -b restore /dev/mapper/virtualmachines-rocks0003p5 $SOURCE/virtualmachines-rocks0003p5.img.000

# Re-create swap
mkswap /dev/mapper/virtualmachines-rocks0003p3

# Delete partition mappings in /dev/mapper
kpartx -dv /dev/virtualmachines/rocks0003

# VM 14: Rocks 5.1 x86_64 HPC Compute Cluster HVM domU (based on CentOS 5.2)
###############################################################################################################

# Add partition mappings in /dev/mapper
kpartx -av /dev/virtualmachines/rocks0004

# Restore MBR
dd if=$SOURCE/virtualmachines-rocks0004.mbr of=/dev/virtualmachines/rocks0004 bs=512 count=1

# Restore partition geometry
sfdisk /dev/virtualmachines/rocks0004 < $SOURCE/virtualmachines-rocks0004.sfdisk

# Restore all filesystems
partimage -e -b restore /dev/mapper/virtualmachines-rocks0004p1 $SOURCE/virtualmachines-rocks0004p1.img.000

partimage -e -b restore /dev/mapper/virtualmachines-rocks0004p2 $SOURCE/virtualmachines-rocks0004p2.img.000

partimage -e -b restore /dev/mapper/virtualmachines-rocks0004p5 $SOURCE/virtualmachines-rocks0004p5.img.000

# Re-create swap
mkswap /dev/mapper/virtualmachines-rocks0004p3

# Delete partition mappings in /dev/mapper
kpartx -dv /dev/virtualmachines/rocks0004

# VM 15: Rocks 5.1 x86_64 HPC Compute Cluster HVM domU (based on CentOS 5.2)
###############################################################################################################

# Add partition mappings in /dev/mapper
kpartx -av /dev/virtualmachines/rocks0005

# Restore MBR
dd if=$SOURCE/virtualmachines-rocks0005.mbr of=/dev/virtualmachines/rocks0005 bs=512 count=1

# Restore partition geometry
sfdisk /dev/virtualmachines/rocks0005 < $SOURCE/virtualmachines-rocks0005.sfdisk

# Restore all filesystems
partimage -e -b restore /dev/mapper/virtualmachines-rocks0005p1 $SOURCE/virtualmachines-rocks0005p1.img.000

partimage -e -b restore /dev/mapper/virtualmachines-rocks0005p2 $SOURCE/virtualmachines-rocks0005p2.img.000

partimage -e -b restore /dev/mapper/virtualmachines-rocks0005p5 $SOURCE/virtualmachines-rocks0005p5.img.000

# Re-create swap
mkswap /dev/mapper/virtualmachines-rocks0005p3

# Delete partition mappings in /dev/mapper
kpartx -dv /dev/virtualmachines/rocks0005

# VM 16: Slackware64 13.0 amd64 HVM domU
###############################################################################################################

# Add partition mappings in /dev/mapper
kpartx -av /dev/virtualmachines/slackware64

# Restore MBR
dd if=$SOURCE/virtualmachines-slackware64.mbr of=/dev/virtualmachines/slackware64 bs=512 count=1

# Restore partition geometry
sfdisk /dev/virtualmachines/slackware64 < $SOURCE/virtualmachines-slackware64.sfdisk

# Restore all filesystems
partimage -e -b restore /dev/mapper/virtualmachines-slackware64p1 $SOURCE/virtualmachines-slackware64p1.img.000

partimage -e -b restore /dev/mapper/virtualmachines-slackware64p2 $SOURCE/virtualmachines-slackware64p2.img.000

# Re-create swap
mkswap /dev/mapper/virtualmachines-slackware64p3

# Delete partition mappings in /dev/mapper
kpartx -dv /dev/virtualmachines/slackware64

# VM 17: Ubuntu 9.10 Karmic Koala Linux HVM domU
###############################################################################################################

# Add partition mappings in /dev/mapper
kpartx -av /dev/virtualmachines/ubuntu910

# Restore MBR
dd if=$SOURCE/virtualmachines-ubuntu910.mbr of=/dev/virtualmachines/ubuntu910 bs=512 count=1

# Restore partition geometry
sfdisk /dev/virtualmachines/ubuntu910 < $SOURCE/virtualmachines-ubuntu910.sfdisk

# Restore all filesystems
partimage -e -b restore /dev/mapper/virtualmachines-ubuntu910p1 $SOURCE/virtualmachines-ubuntu910p1.img.000

# Re-create swap
mkswap /dev/mapper/virtualmachines-ubuntu910p5

# Delete partition mappings in /dev/mapper
kpartx -dv /dev/virtualmachines/ubuntu910

# VM 18: Windows XP Home Edition SP3 32-bit HVM domU with VGA passthrough (requires Intel VT-d)
###############################################################################################################

# Add partition mappings in /dev/mapper
kpartx -av /dev/virtualmachines/winxphome32

# Restore MBR
dd if=$SOURCE/virtualmachines-winxphome32.mbr of=/dev/virtualmachines/winxphome32 bs=512 count=1

# Restore partition geometry
sfdisk /dev/virtualmachines/winxphome32 < $SOURCE/virtualmachines-winxphome32.sfdisk

# Restore all filesystems
partimage -e -b restore /dev/mapper/virtualmachines-winxphome32p1 $SOURCE/virtualmachines-winxphome32p1.img.000

# Delete partition mappings in /dev/mapper
kpartx -dv /dev/virtualmachines/winxphome32

###############################################################################################################
###############################################################################################################

# Deactivate Logical Volume Manager
vgchange -an

# Sync filesystems
sync

# Reboot the machine
reboot

###############################################################################################################
# EOF
###############################################################################################################
</SCRIPT>

-- 
Mr. Teo En Ming (Zhang Enming) Dip(Mechatronics) BEng(Hons)(Mechanical Engineering)
Alma Maters:
(1) Singapore Polytechnic
(2) National University of Singapore
My Primary Blog: http://teo-en-ming-aka-zhang-enming.blogspot.com
My Secondary Blog: http://enmingteo.wordpress.com
My Youtube videos: http://www.youtube.com/user/enmingteo
Email: space.time.universe@xxxxxxxxx
Mobile Phone (Starhub Prepaid): +65-8369-2618
Street: Bedok Reservoir Road
Country: Singapore
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