BMR in Windows Hyper-V

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The following article discusses the steps needed to create a customized CentOS LiveCD, with support for Microsoft Hyper-V Virtual Machines, for the purpose of performing Bare Metal Restores via the R1Soft CDP Server. It is meant to be a Proof-of-Concept. The methods outlined can likely be used to create Live ISOs using a variety of distros.

 Creating a LiveCD isn't as daunting a task as many people think. My working environment was a standard CentOS 5.2 installation.
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\[root@xensource \~\]# cat /etc/redhat-release
CentOS release 5.2 (Final)
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If you don't already have "squashfs-tools" install, use yum to install it.
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\[root@xensource \~\]# rpm \-qa \| grep \-i squash
squashfs-tools-3.0-4
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Start off by downloading the latest CentOS LiveCD from your favorite mirror: CentOS-5.3-i386-LiveCD.iso

 Once downloaded, create a mount point, mount the ISO, and look at the contents (these are the component you will be working with):
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 \[root@xensource \~\]# mkdir /mnt/centlive
\[root@xensource \~\]# mount \-o loop CentOS-5.3-i386-LiveCD.iso /mnt/centlive
\[root@xensource \~\]# cd /mnt/centlive
\[root@xensource centlive\]# ls \-lhs
total 4.0K
2.0K dr-xr-xr-x 2 root root 2.0K Apr  7 22:02 isolinux
2.0K dr-xr-xr-x 2 root root 2.0K Apr  7 22:05 LiveOS
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Inside the 'LiveOS' directory is the squashfs image:
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 \[root@xensource LiveOS\]# ls \-lha \| grep squash
\-r-xr-xr-x 1 root root 678M Apr  7 22:18 squashfs.img
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We cannot work within this directory tree since the ISO mount point is read-only. Create a new working directory and copy the contents of /mnt/centlive to it:
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\[root@xensource LiveOS\]# mkdir /mnt/hyper-v/
\[root@xensource centlive\]# cp \-R * /mnt/hyper-v/
\[root@xensource centlive\]# cd /mnt/hyper-v/
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 Before proceeding any further, you will need to download  Linux Integration Components for Windows Server 2008 Hyper-V from Microsoft's website TO A WINDOWS MACHINE:

 [http://www.microsoft.com/downloads/details.aspx?FamilyID=AB7F4983-93C5-4A70-8C79-0642F0D59EC2&displaylang=en]

 Run the executable and it will extract another ISO image containing the necessary drivers. You can either extract the ISO to a folder in Windows or mount the ISO in Linux. Either way, the contents of the ISO need to get into our working environment:
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\[root@xensource \~\]# ls \-lha LinuxIC\ v2\ RC.iso
\-rw-r\--r-\- 1 root root 1.4M Feb 17 14:08 LinuxIC v2 RC.iso
\[root@xensource \~\]# mkdir /mnt/linux_ic_drivers
\[root@xensource \~\]# mount \-o loop LinuxIC\ v2\ RC.iso /mnt/linux_ic_drivers
\[root@xensource \~\]# cd /mnt/linux_ic_drivers
\[root@xensource linux_ic_drivers\]# ls
drivers  setup.pl  v2v
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Return back to the /mnt/hyper-v/LiveOS and unsquash the image file (it will create a "squashfs-root" directory):
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\[root@xensource LiveOS\]# unsquashfs squashfs.img

created 2 files
created 2 directories
created 0 symlinks
created 0 devices
created 0 fifos
\[root@xensource LiveOS\]# ls
osmin.img  squashfs.img  squashfs-root
\[root@xensource LiveOS\]# cd squashfs-root
\[root@xensource squashfs-root\]# ls
LiveOS  yum.conf
\[root@xensource squashfs-root\]# cd LiveOS
\[root@xensource LiveOS\]# ls
ext3fs.img
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Inside the LiveOS directory is the ext3fs.img that we will need to modify. Begin by mounting it and checking it's contents:
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 \[root@xensource LiveOS\]# mkdir /tmp/ext3
\[root@xensource LiveOS\]# mount \-o loop ext3fs.img /tmp/ext3
\[root@xensource LiveOS\]# cd /tmp/ext3/
\[root@xensource ext3\]# ls
bin   dev  home  lost+found  misc  opt   root  selinux  sys  usr
boot  etc  lib   media       mnt   proc  sbin  srv      tmp  var
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Building Micorsoft's drivers is no different than building other kernel modules for Linux. You need to have GCC, kenrel-headers, make, etc... installed on the machine to do so. By default, the CentOS LiveCD doesn't have these and you will not be able to use Yum to install them once the CD is booted up since there will be no NIC detected. For the sake of simplicity, I created 1 directory (called rpms) within the 'ext3' image and place all neccessary compenents in it:
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\[root@xensource rpms\]# ls
binutils-2.17.50.0.6-9.el5.i386.rpm
gcc-4.1.2-44.el5.i386.rpm
glibc-devel-2.5-34.i386.rpm
glibc-headers-2.5-34.i386.rpm
kernel-devel-2.6.18-128.1.6.el5.i686.rpm
kernel-headers-2.6.18-128.1.6.el5.i386.rpm
libgomp-4.3.2-7.el5.i386.rpm
linux-agent-32-1.62.0-generic.run
linux_ic_drivers (DIRECTORY FROM THE MS Linux Integration Components ISO)
make-3.81-15.el5.i386.rpm
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We have a full linux directory tree structure in /tmp/ext3. You can chroot into it and install the RPMs now, or do it once you boot into the CD:
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 \[root@xensource tmp\]# chroot /tmp/ext3/ /bin/bash
\[root@xensource /\]# cd rpms/
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Install the RPMs in this directory (you can delete them one done). Once done, we need to repackage the ISO. Begin by exiting the 'chroot' and unmount the ext3 image:
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 \[root@xensource rpms\]# exit
exit
\[root@xensource tmp\]# umount /tmp/ext3/
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Little endian filesystem, data block size 65536, compressed data, compressed metadata, compressed fragments
Filesystem size 740270.99 Kbytes (722.92 Mbytes)
        17.65% of uncompressed filesystem size (4194560.47 Kbytes)
Inode table size 84972 bytes (82.98 Kbytes)
        32.39% of uncompressed inode table size (262338 bytes)
Directory table size 59 bytes (0.06 Kbytes)
        100.00% of uncompressed directory table size (59 bytes)
Number of duplicate files found 0
Number of inodes 4
Number of files 2
Number of fragments 1
Number of symbolic links  0
Number of device nodes 0
Number of fifo nodes 0
Number of socket nodes 0
Number of directories 2
Number of uids 1
        root (0)
Number of gids 0
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Next, replace the existing squashfs.img file in our working directory  (/mnt/hyper-v/LiveOS) with the one we just created. Last we will make a little edit to the isolinux.cfg file. I changed:

{color:#0000ff}append initrd=initrd0.img root=CDLABEL=CentOS-5.3-i386-LiveCD rootfstype=iso9660 ro quiet liveimg 3{color}

To \->  {color:#0000ff}append initrd=initrd0.img root=CDLABEL=Hyper-V-BMR-i386 rootfstype=iso9660 ro quiet liveimg 3{color}

{color:#ff0000}\**\* The root=CDLABEL value MUST be used in the mkisofs command or the new LiveCD will not boot properly\!\!{color}\\
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\[root@xensource isolinux\]# mkisofs \-o /root/HyperV25-BMR.iso \-b isolinux/isolinux.bin \-c isolinux/boot.cat \-no-emul-boot \-boot-load-size 4 \-boot-info-table \-r \-R \-J \-V "Hyper-V-BMR-i386" \-A "Hyper-V-BMR-i386" \-T /mnt/hyper-v/
 INFO:   UTF-8 character encoding detected by locale settings.
        Assuming UTF-8 encoded filenames on source filesystem,
        use \-input-charset to override.
mkisofs: Value too large for defined data type. File /mnt/hyper-v/LiveOS/squashfs-root/LiveOS/ext3fs.img is too large - ignoring
Size of boot image is 4 sectors \-> No emulation
  1.42% done, estimate finish Thu Jun  4 06:49:05 2009
  2.83% done, estimate finish Thu Jun  4 06:49:05 2009
\*\**\**\**\**\**\**\**\**\**\**edited*\************************************\*

 98.90% done, estimate finish Thu Jun  4 06:49:20 2009
Total translation table size: 5811
Total rockridge attributes bytes: 2412
Total directory bytes: 8192
Path table size(bytes): 70
Max brk space used 0
353880 extents written (691 MB)
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Transfer your newly created ISO to your Hyper-V machine and boot the VM you wish to BMR with the ISO.
Once at a command prompt, build the drivers (the drivers will build, but the script will throw an error because it is a LiveCD):
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\# /rpms/linux_ic_drivers/setup.pl drivers
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Load the newly built drivers manually.
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\# insmod /rpms/linux_ic_rc/drivers/dist/vmbus/vmbus.ko
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Verify the the appropriarte drivers are loaded (looking for 'netvsc'):
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 \[root@localhost vmbus\]# lsmod \| grep vsc
netvsc                 45616  0
vmbus                  56904  1 netvsc
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Restart networking on the machine (/etc/init.d/network restart) and your NIC should now be detected:
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 \[root@localhost vmbus\]# ifconfig  \| grep seth0
seth0     Link encap:Ethernet  HWaddr 00:15:5D:C8:23:00
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Install the R1Soft agent in 'recovery mode' : [http://wiki.r1soft.com/display/kb/Starting+Buagent+for+BMR] and you can start BMR'ing :-)
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Product Component
Effected O/S
Status
Fixed or to be in Release
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CDP Server / Agent / All
Linux
Fixed / Won't Fix / Cannot Reproduce / Investigating / Fix Scheduled for Future Release
[2.X.Y|CDP Server 2.12 Release Notes]
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