Virtualization Guide
- About This Manual
- I Introduction
- II Managing Virtual Machines with
libvirt - III Common Tasks
- IV Managing Virtual Machines with Xen
- 18 Setting Up a Virtual Machine Host
- 19 Virtual Networking
- 20 Managing a Virtualization Environment
- 21 Block Devices in Xen
- 22 Virtualization: Configuration Options and Settings
- 23 Administration Tasks
- 24 XenStore: Configuration Database Shared between Domains
- 25 Xen as a High-Availability Virtualization Host
- V Managing Virtual Machines with QEMU
- VI Managing Virtual Machines with LXC
- Glossary
- A Virtual Machine Drivers
- B Appendix
- C XM, XL Toolstacks and Libvirt framework
- D Documentation Updates
- E GNU Licenses
15 Save and Restore of Virtual Machines
15.1 Saving Virtual Machines #
The save operation preserves the exact state of the virtual machine’s memory. The operation is slightly similar to hibernating a computer. The virtual machine is off, but it can be quickly restored to its previously saved running condition. The operation does not make a copy of any portion of the virtual machine’s virtual disk.
When saved, the virtual machine is paused, its current memory state saved to a location you specify, and then the virtual machine is stopped. The amount of time taken to save the virtual machine depends on the amount of memory allocated. When saved, a virtual machine’s memory is returned to the pool of memory available on the host.
The restore operation is used to return a saved virtual machine to its original running state.
Important
After using the save operation, do not boot, start, or run a virtual machine that you intend to restore. If the virtual machine is at any time restarted before it is restored, the saved memory state file becomes invalid and should not be used to restore.
Procedure 15.1: Save a Virtual Machine’s Current State (Virtual Machine Manager) #
Make sure the virtual machine to be saved is running.
Select the virtual machine.
Click to view the virtual machine console, then to view virtual machine information.
Select › › from the menu.
Name and save the file.
15.2 Restoring Virtual Machines #
The restore operation loads a virtual machine’s previously saved memory state file and starts the virtual machine. The virtual machine does not boot the operating system but resumes at the point where it was previously saved. The operation is slightly similar to coming out of hibernation.
Important
After using the save operation, do not boot, start, or run the virtual machine you intend to restore. If the virtual machine is at any time restarted before it is restored, the saved memory state file becomes invalid and should not be used to restore.
Procedure 15.2: Restore a Virtual Machine’s Current State (Virtual Machine Manager) #
Make sure the virtual machine to be restored has not been started since you ran the save operation.
Run the Virtual Machine Manager.
Select the hypervisor and connection used to restore the virtual machine. On the local machine, this is
localhost. Right-click it and choose from the context menu.In the window, choose › from the drop-down box.
Specify the previously saved file.
Click .
The virtual machine and the guest operating system are restored to the previously saved state.