Difference between revisions of "KVM"

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(→‎Accessing services on KVM guests behind a NAT)
(→‎Accessing services on KVM guests behind a NAT)
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I am using the virtio-Interface (performance).
 
I am using the virtio-Interface (performance).
  
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=== Control NAT rules ===
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iptables -nvL -t nat
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=== Delete NAT rules ===
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iptables -t nat -D PREROUTING 1
  
 
== Backup KVM ==  
 
== Backup KVM ==  

Revision as of 11:31, 30 October 2013

Using VirtualBox and KVM together

Using VirtualBox and KVM together at the same server at the same time is NOT possible!!!

Use VirtualBox 

sudo service qemu-kvm stop
sudo service vboxdrv start

OR use KVM 

sudo service vboxdrv stop
sudo service qemu-kvm start

Decide!

Migration from VirtualBox to KVM

This boils down to

  1. having a lot of time
  2. having a lot of free harddisk space
  3. creating a clone of the vbox-machine with VBoxManage clonehd (this can take a looooong time!). Kloning is the easiest way of getting rid of snapshots of an existing virtual machine.
  4. converting the images from vdi to qcow-format with qemu-img convert
  5. creating and configuring a new kvm-guest
  6. adding some fou to NAT with a qemu-hook (see next section)

To clone an image - on the same machine - you have to STOP kvm and start vboxdr (see above). Also be aware, that the raw-images take up a lot of space! 

# The conversion can take some time. Other virtual machines are not accessible in this time
VBoxManage clonehd -format RAW myOldVM.vdi /home/vm-exports/myNewVM.raw
0%...

cd /home/vm-exports/
qemu-img convert -f raw myNewVM.raw -O qcow2 myNewVM.qcow

Cloning a Snapshot: 

# for a snapshot do (not tested)
cd /to/the/SnapShot/dir
VBoxManage clonehd -format RAW "SNAPSHOT_UUID" /home/vm-exports/myNewVM.raw

Accessing services on KVM guests behind a NAT

This is done by editing a hook-script for quemu: 

/etc/libvirt/hooks/qemu

I am referring to this article:

which ist mentioned in the libvirt wiki:

I installed the qemu-python script of the first article under ubuntu 12.04 LTS, which worked like expected.

So I can access a port in the virtualmachine-guest with the IP/Port of the host (!). From within the host, it is possible to reach the guest via it's real ip. I am using the virtio-Interface (performance).

Control NAT rules

iptables -nvL -t nat

Delete NAT rules

iptables -t nat -D PREROUTING 1

Backup KVM

Via LVM

LiveBackup

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