copy_device_to_device

copy from source device to destination device

The four calls copy_device_to_device, copy_device_to_file, copy_file_to_device, and copy_file_to_file let you copy from a source ( device|file) to a destination (device|file).

Partial copies can be made since you can specify optionally the source offset, destination offset and size to copy. These values are all specified in bytes. If not given, the offsets both default to zero, and the size defaults to copying as much as possible until we hit the end of the source.

The source and destination may be the same object. However overlapping regions may not be copied correctly.

If the destination is a file, it is created if required. If the destination file is not large enough, it is extended.

If the destination is a file and the append flag is not set, then the destination file is truncated. If the append flag is set, then the copy appends to the destination file. The append flag currently cannot be set for devices.

If the sparse flag is true then the call avoids writing blocks that contain only zeroes, which can help in some situations where the backing disk is thin-provisioned. Note that unless the target is already zeroed, using this option will result in incorrect copying.

Parameters:

this	A GuestfsSession object
optargs	a GuestfsCopyDeviceToDevice containing optional arguments

Returns:

true on success, false on error