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Content Owner: Roman Macek | ||||
Summary
Yes; Including RAM
Details
RHV 3.1 introduced the new ability to take Live Snapshots of VMs and has an enhanced Snapshot management interface (maintained with 3.3).
New in RHV 3.3: Snapshots now include the state of a virtual machines memory as well as disk. In addition a new Create Snapshot button has been added to the action panel of the Virtual Machines tab, and as a context menu item when a virtual machine is selected.
New in RHV 3.4: The admin portal now allows to preview, commit and manage snapshots of individual disks within a VM.
New in RHV 3.5: Ability to Live Merge snapshots, allowing to remove intermediate snapshots while VM is running
Taking a snapshot in RHV involves the following possible actions:
- Creation (obviously)
- Previews (involves previewing a snapshot to determine whether or not to restore the system to this snapshot - when it is previewed, a new (COW) preview layer is copied from the snapshot being previewed. The guest interacts with the preview instead of the actual snapshot volume. The preview can then be committed to restore the
guest data to the state captured in the snapshot or alternatively the admin can select Undo to discard the preview layer of the viewed snapshot.
- Deletion (deleting a restoration point that is no longer required)
Notes for Live Snapshots:
- VM with a guest agent that supports quiescing can ensure filesystem consistency across live snapshots. Red Hat Network registered Red Hat Enterprise Linux guests can install the qemu-guest agent to enable quiescing before snapshots (VDSM uses libvirt to communicate with the agent to prepare for a snapshot).
- All live snapshots are attempted with quiescing enabled. If the snapshot command fails because there is no compatible guest agent present, the live snapshot is re-initiated without the use-quiescing flag.
Please note: When a virtual machine is reverted with quiesced filesystems, it boots cleanly with no filesystem check required.
Reverting the previous snapshot using an un-quiesced filesystem however requires a filesystem check on boot.
New in RHV 3.3: Snapshots now include the state of a virtual machines memory as well as disk. In addition a new Create Snapshot button has been added to the action panel of the Virtual Machines tab, and as a context menu item when a virtual machine is selected.
New in RHV 3.4: The admin portal now allows to preview, commit and manage snapshots of individual disks within a VM.
New in RHV 3.5: Ability to Live Merge snapshots, allowing to remove intermediate snapshots while VM is running
Taking a snapshot in RHV involves the following possible actions:
- Creation (obviously)
- Previews (involves previewing a snapshot to determine whether or not to restore the system to this snapshot - when it is previewed, a new (COW) preview layer is copied from the snapshot being previewed. The guest interacts with the preview instead of the actual snapshot volume. The preview can then be committed to restore the
guest data to the state captured in the snapshot or alternatively the admin can select Undo to discard the preview layer of the viewed snapshot.
- Deletion (deleting a restoration point that is no longer required)
Notes for Live Snapshots:
- VM with a guest agent that supports quiescing can ensure filesystem consistency across live snapshots. Red Hat Network registered Red Hat Enterprise Linux guests can install the qemu-guest agent to enable quiescing before snapshots (VDSM uses libvirt to communicate with the agent to prepare for a snapshot).
- All live snapshots are attempted with quiescing enabled. If the snapshot command fails because there is no compatible guest agent present, the live snapshot is re-initiated without the use-quiescing flag.
Please note: When a virtual machine is reverted with quiesced filesystems, it boots cleanly with no filesystem check required.
Reverting the previous snapshot using an un-quiesced filesystem however requires a filesystem check on boot.
