How to Backup and Restore MBR within Logical Volumes?

Fri Nov 13 13:52:15 UTC 2009

On Fri, Nov 13, 2009 at 9:17 PM, Dustin Henning
<Dustin.Henning at prd-inc.com>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 at redhat.com [mailto:fedora-xen-bounces at redhat.com]
> 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 at lists.xensource.com; 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 at gmail.com
> 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 at kobaltwit.be> 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 at kobaltwit.be
>
>
> _______________________________________________
> Xen-users mailing list
> Xen-users at lists.xensource.com
> http://lists.xensource.com/xen-users
>
>
>
>
>
>
Hi Dustin,

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

Article: MBR tricks with LinuxLink:
http://www.tuxation.com/mbr-tricks-with-linux.htmlHere 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 at gmail.com
# MSN: teoenming at hotmail.com
# 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 at gmail.com
Mobile Phone (Starhub Prepaid): +65-8369-2618
Street: Bedok Reservoir Road
Country: Singapore
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