Difference between revisions of "stoney conductor: VM Backup"

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= Overview =
 
= Overview =
 
This page describes how the VMs and VM-Templates are backed-up inside the [http://www.stoney-cloud.org stoney cloud].
 
This page describes how the VMs and VM-Templates are backed-up inside the [http://www.stoney-cloud.org stoney cloud].
 
= State of the art =
 
  
 
= Basic idea =
 
= Basic idea =
 +
The main idea to backup a VM or a VM-Template is, to divide the task into three subtasks:
 +
* Snapshot: Save the machines state (CPU, Memory and Disk)
 +
* Merge: Merge the Disk-Snapshot with the live-image
 +
* Retain: Export the snapshot files
 +
A more detailed and technical description for these three sub-processes can be found in the following sub-chapters.
 +
 +
== Snapshot ==
 +
# Create a snapshot with state:
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#* Save the VMs state: <code>virsh save my-vm my-vm.state</code>
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#* Rename the actual disk image: <code>mv my-vm.qcow2 my-vm-backup.qcow2</code>.
 +
#* Create the new disk image with the old as backing file: <code>qemu-img create -f qcow2 -b my-vm-backup.qcow2 my-vm.qcow2</code>.
 +
#* Set correct ownership and permission to the newly created image:
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#** <code>chown root:vm-storage my-vm.qcow2</code>.
 +
#** <code>chmod 660 my-vm.qcow2</code>.
 +
#* Restore the VMs state:  <code>virsh restore my-vm.state</code>.
 +
# Merge the disk images my-vm.qcow2 and my-vm-snap.qcow2 to a single image: <code>virsh qemu-monitor-command my-vm --hmp "block_stream drive-virtio-disk0"</code>.
 +
# Move the files to the backup location:
 +
#* Move the old disk image to the backup location and add the date as suffix to not overwrite older backups: <code>mv my-vm-backup.qcow2 /path/to/backup/my-vm-backup.qcow2.date</code>
 +
#* Move the state file to the backup location and add the date as suffix to not overwrite older backups: <code>mv my-vm.state /path/to/backup/my-vm.state.date</code>
 +
 +
== Merge ==
 +
 +
== Retain ==
 +
 +
 +
= State of the art =
  
 
= Next steps =  
 
= Next steps =  
  
 
[[Category: stoney conductor]]
 
[[Category: stoney conductor]]

Revision as of 13:29, 22 October 2013

Overview

This page describes how the VMs and VM-Templates are backed-up inside the stoney cloud.

Basic idea

The main idea to backup a VM or a VM-Template is, to divide the task into three subtasks:

  • Snapshot: Save the machines state (CPU, Memory and Disk)
  • Merge: Merge the Disk-Snapshot with the live-image
  • Retain: Export the snapshot files

A more detailed and technical description for these three sub-processes can be found in the following sub-chapters.

Snapshot

  1. Create a snapshot with state:
    • Save the VMs state: virsh save my-vm my-vm.state
    • Rename the actual disk image: mv my-vm.qcow2 my-vm-backup.qcow2.
    • Create the new disk image with the old as backing file: qemu-img create -f qcow2 -b my-vm-backup.qcow2 my-vm.qcow2.
    • Set correct ownership and permission to the newly created image:
      • chown root:vm-storage my-vm.qcow2.
      • chmod 660 my-vm.qcow2.
    • Restore the VMs state: virsh restore my-vm.state.
  2. Merge the disk images my-vm.qcow2 and my-vm-snap.qcow2 to a single image: virsh qemu-monitor-command my-vm --hmp "block_stream drive-virtio-disk0".
  3. Move the files to the backup location:
    • Move the old disk image to the backup location and add the date as suffix to not overwrite older backups: mv my-vm-backup.qcow2 /path/to/backup/my-vm-backup.qcow2.date
    • Move the state file to the backup location and add the date as suffix to not overwrite older backups: mv my-vm.state /path/to/backup/my-vm.state.date

Merge

Retain

State of the art

Next steps