8 VBoxManage 8.14 VBoxManage snapshot This command is used to control snapshots from the command line. A snapshot consists of a complete copy of the virtual machine settings, copied at the time when the snapshot was taken, and optionally a virtual machine saved state file if the snapshot was taken while the machine was running. After a snapshot has been taken, VirtualBox creates differencing hard disk for each normal hard disk associated with the machine so that when a snapshot is restored, the contents of the virtual machine’s virtual hard disks can be quickly reset by simply dropping the pre-existing differencing files. The take operation takes a snapshot of the current state of the virtual machine. You must supply a name for the snapshot and can optionally supply a description. The new snapshot is inserted into the snapshots tree as a child of the current snapshot and then becomes the new current snapshot. The delete operation deletes a snapshot (specified by name or by UUID). This can take a while to finish since the differencing images associated with the snapshot might need to be merged with their child differencing images. The restore operation will restore the given snapshot (specified by name or by UUID) by resetting the virtual machine’s settings and current state to that of the snapshot. The previous current state of the machine will be lost. After this, the given snapshot becomes the new “current” snapshot so that subsequent snapshots are inserted under the snapshot from which was restored. The restorecurrent operation is a shortcut to restore the current snapshot (i.e. the snapshot from which the current state is derived). This subcommand is equivalent to using the “restore” subcommand with the name or UUID of the current snapshot, except that it avoids the extra step of determining that name or UUID. With the edit operation, you can change the name or description of an existing snapshot. With the showvminfo operation, you can view the virtual machine settings that were stored with an existing snapshot. 8.15 VBoxManage closemedium This commands removes a hard disk, DVD or floppy image from a VirtualBox media registry.2 Optionally, you can request that the image be deleted. You will get appropriate diagnostics that the deletion failed, however the image will become unregistered in any case. 8.16 VBoxManage storageattach This command attaches/modifies/removes a storage medium connected to a storage controller that was previously added with the storagectl command (see the previous section). The syntax is as follows: VBoxManage storageattach uuid|vmname --storagectl name --port number --device number [--type dvddrive|hdd|fdd] [--medium none|emptydrive| uuid|filename|host:drive|iscsi] [--mtype normal|writethrough|immutable|shareable] [--comment text] [--passthrough on|off] [--bandwidthgroup name|none] 2Before VirtualBox 4.0, it was necessary to call VBoxManage openmedium before a medium could be attached to a virtual machine that call “registered” the medium with the global VirtualBox media registry. With VirtualBox 4.0 this is no longer necessary media are added to media registries automatically. The “closemedium” call has been retained, however, to allow for explicitly removing a medium from a registry. 119