Public Attributes | |
readonly attribute wstringUUID | id |
UUID of the snapshot. | |
attribute wstring | name |
Short name of the snapshot. | |
attribute wstring | description |
Optional description of the snapshot. | |
readonly attribute long long | timeStamp |
Time stamp of the snapshot, in milliseconds since 1970-01-01 UTC. | |
readonly attribute boolean | online |
true if this snapshot is an online snapshot and false otherwise. | |
readonly attribute IMachine | machine |
Virtual machine this snapshot is taken on. | |
readonly attribute ISnapshot | parent |
Parent snapshot (a snapshot this one is based on), or null if the snapshot has no parent (i.e. | |
readonly attribute ISnapshot[] | children |
Child snapshots (all snapshots having this one as a parent). |
Together with the differencing media that are created when a snapshot is taken, a machine can be brought back to the exact state it was in when the snapshot was taken.
The ISnapshot interface has no methods, only attributes; snapshots are controlled through methods of the IConsole interface which also manage the media associated with the snapshot. The following operations exist:
The differencing images will then receive all data written to the machine's media, while their parent (base) images remain unmodified after the snapshot has been taken (see IMedium for details about differencing images). This simplifies restoring a machine to the state of a snapshot: only the differencing images need to be deleted.
The current machine state is not changed by taking a snapshot. If the machine is running, it will resume execution after the snapshot has been taken. After calling this, IMachine::currentSnapshot is set to the snapshot just created.
This destroys the machine's current state. After calling this, IMachine::currentSnapshot is set to the snapshot that was restored.
This does not change the current machine state, but instead frees the resources allocated when the snapshot was taken: the settings and machine state file are deleted (if any), and the snapshot's differencing image for each of the machine's media gets merged with its parent image.
Neither the current machine state nor other snapshots are affected by this operation, except that parent media will be modified to contain the disk data associated with the snapshot being deleted.
When deleting the current snapshot, the IMachine::currentSnapshot attribute is set to the current snapshot's parent or NULL if it has no parent. Otherwise the attribute is unchanged.
Each snapshot contains the settings of the virtual machine (hardware configuration etc.). In addition, if the machine was running when the snapshot was taken (IMachine::state is MachineState_Running), the current VM state is saved in the snapshot (similarly to what happens when a VM's state is saved). The snapshot is then said to be online because when restoring it, the VM will be running.
If the machine is saved (MachineState_Saved), the snapshot receives a copy of the execution state file (IMachine::stateFilePath).
Otherwise, if the machine was not running (MachineState_PoweredOff or MachineState_Aborted), the snapshot is offline; it then contains a so-called "zero execution state", representing a machine that is powered off.
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readonly attribute wstringUUID ISnapshot::id |
UUID of the snapshot.
attribute wstring ISnapshot::name |
Short name of the snapshot.
attribute wstring ISnapshot::description |
Optional description of the snapshot.
readonly attribute long long ISnapshot::timeStamp |
Time stamp of the snapshot, in milliseconds since 1970-01-01 UTC.
readonly attribute boolean ISnapshot::online |
true
if this snapshot is an online snapshot and false
otherwise.
When this attribute is true
, the IMachine::stateFilePath attribute of the machine object associated with this snapshot will point to the saved state file. Otherwise, it will be an empty string.
readonly attribute IMachine ISnapshot::machine |
Virtual machine this snapshot is taken on.
This object stores all settings the machine had when taking this snapshot.
readonly attribute ISnapshot ISnapshot::parent |
Parent snapshot (a snapshot this one is based on), or null
if the snapshot has no parent (i.e.
is the first snapshot).
readonly attribute ISnapshot [] ISnapshot::children |
Child snapshots (all snapshots having this one as a parent).