T
topi
Guest
Recently, I had to migrate a physical machine to Proxmox (P2V), but on a smaller disk. As you can imagine I consulted the documentation http://pve.proxmox.com/wiki/Migration_of_servers_to_Proxmox_VE#How_to_migrate_from_a_physical_machine_to_a_VM.2C_on_a_smaller_partition But I was not completely satisfied with what I read, but in any case I encourage you to read the wiki before reading this post.
With a little thinking about all of that and some tests I followed another way. My idea was to use dd for the system partition (/). It's possible because in my case it's size kept the same. So only used the filesystem level copy to the partitions with a smaller size. I also noticed another way to do with CloneZilla : http://sourceforge.net/projects/clonezilla/files/clonezilla_live_doc/CloningToSmallerDrive_0.1/
It works for me, my VM is now running on Proxmox. But be extremely careful with your production machines. I can't give you any guarantee, specially if your configuration differs (size, partition type, MBR type, bootloader, OS windows ...), or there may be some mistakes in my explanation.
And obviously, I expect your comments or your experiments.
The physical machine
The machine works with SLES 11. The original disk was 2 TiB, but only 800 GiB where really used. My machine had a 50GiB /dev/sda1 partition for /, a 8GiB /dev/sda2 partition for swap, and the rest for a LVM partition /dev/sda3 for home, data ... (mostly empty).
I wanted to virtualize it into a 1 TiB disk on Proxmox.
The steps
On Proxmox
1. Create the VM on Proxmox with a 1 TiB disk size.
2. Boot the VM with a livecd. gPparted is not bad for that.
3. Create the partition /dev/sda1 50GiB. At least the same size of the original (or greater).
4. Create the partition /dev/sda2 8 GiB for swap. The size here could be adapted.
5. Create the third partition /dev/sda3 with the rest of the size. Choose to create a LVM partition or a “normal” partition as you like. Remarks here that new partition is smaller that the physical one.
On the physical machine
6. Boot you physical machine with a livecd (gParted, systemrecue …).
7. Make a dd (by example on an external disk) of the MBR (my MBR is a msdos one, not a GPT), but only the 440 first bytes (we don't want to copy the disk signature and the partition table). Here there is an explanation of why : http://forums.opensuse.org/install-...-mbr-grub-dual-boot-opensuse-11-1-win-xp.html
8. Make a dd (by example on an external disk) of the partitions you want to clone. In my case that was only /dev/sda1 for the system. I couldn’t use dd with /dev/sda3 because the virtualized partition will be smaller. Please consult the documentation of dd to understand how exactly it works.
The VM onProxmox
9. Boot you VM with a livecd (gParted, systemrecue …)
10. Restore the 440 first bytes of the MBR from the external disk.
11. Restore the /dev/sda1 partition
12. Mount /dev/sda1 into /mnt
13. Check and if necessary adapt the grub files : /mnt/sda1/etc/grub.conf, /mnt/sda1/boot/grub/device.map, /mnt/sda1/boot/grub/menu.lst
15. Mount the third partition (data one) in the hierarchy by adapting fstab
14. Copy the data of /dev/sda3 from the physical machine to the virtual one. Rsync works great or fsarchive if you want. /data corresponds to the mounted partition /dev/sda3
15. Restart your VM and see if all is OK. It was the case for me.
With a little thinking about all of that and some tests I followed another way. My idea was to use dd for the system partition (/). It's possible because in my case it's size kept the same. So only used the filesystem level copy to the partitions with a smaller size. I also noticed another way to do with CloneZilla : http://sourceforge.net/projects/clonezilla/files/clonezilla_live_doc/CloningToSmallerDrive_0.1/
It works for me, my VM is now running on Proxmox. But be extremely careful with your production machines. I can't give you any guarantee, specially if your configuration differs (size, partition type, MBR type, bootloader, OS windows ...), or there may be some mistakes in my explanation.
And obviously, I expect your comments or your experiments.
The physical machine
The machine works with SLES 11. The original disk was 2 TiB, but only 800 GiB where really used. My machine had a 50GiB /dev/sda1 partition for /, a 8GiB /dev/sda2 partition for swap, and the rest for a LVM partition /dev/sda3 for home, data ... (mostly empty).
I wanted to virtualize it into a 1 TiB disk on Proxmox.
The steps
On Proxmox
1. Create the VM on Proxmox with a 1 TiB disk size.
2. Boot the VM with a livecd. gPparted is not bad for that.
3. Create the partition /dev/sda1 50GiB. At least the same size of the original (or greater).
4. Create the partition /dev/sda2 8 GiB for swap. The size here could be adapted.
5. Create the third partition /dev/sda3 with the rest of the size. Choose to create a LVM partition or a “normal” partition as you like. Remarks here that new partition is smaller that the physical one.
On the physical machine
6. Boot you physical machine with a livecd (gParted, systemrecue …).
7. Make a dd (by example on an external disk) of the MBR (my MBR is a msdos one, not a GPT), but only the 440 first bytes (we don't want to copy the disk signature and the partition table). Here there is an explanation of why : http://forums.opensuse.org/install-...-mbr-grub-dual-boot-opensuse-11-1-win-xp.html
Code:
dd if=/dev/sda of=mbrsda bs=440 count=1
Code:
dd if=/dev/sda of=ddsda1The VM onProxmox
9. Boot you VM with a livecd (gParted, systemrecue …)
10. Restore the 440 first bytes of the MBR from the external disk.
Code:
dd if=mbrsda of=/dev/sda bs=440 count=1
Code:
dd if=ddsda1 of=/dev/sda1
Code:
mkdir /mnt/sda1
mount /dev/sda1 /mnt/sda115. Mount the third partition (data one) in the hierarchy by adapting fstab
Code:
vi /mnt/sda1/etc/fstab
mount -a
Code:
rsync -az /data root@10.17.X.X:/data