def create_cow_image(backing_file, path, size=None):
"""Create COW image
Creates a COW image with the given backing file
:param backing_file: Existing image on which to base the COW image
:param path: Desired location of the COW image
"""
base_cmd = [get_qemu_img_path(), 'create', '-f', 'qcow2']
cow_opts = []
if backing_file:
cow_opts += ['backing_file=%s' % backing_file]
base_details = images.qemu_img_info(backing_file)
else:
base_details = None
# This doesn't seem to get inherited so force it to...
# http://paste.ubuntu.com/1213295/
# TODO(harlowja) probably file a bug against qemu-img/qemu
if base_details and base_details.cluster_size is not None:
cow_opts += ['cluster_size=%s' % base_details.cluster_size]
# For now don't inherit this due the following discussion...
# See: http://www.gossamer-threads.com/lists/openstack/dev/10592
# if 'preallocation' in base_details:
# cow_opts += ['preallocation=%s' % base_details['preallocation']]
if base_details and base_details.encryption:
cow_opts += ['encryption=%s' % base_details.encryption]
if size is not None:
cow_opts += ['size=%s' % size]
if cow_opts:
# Format as a comma separated list
csv_opts = ",".join(cow_opts)
cow_opts = ['-o', csv_opts]
cmd = base_cmd + cow_opts + [path]
execute(*cmd)
def get_disk_type(path):
"""Retrieve disk type (raw, qcow2, lvm) for given file."""
if path.startswith('/dev'):
return 'lvm'
elif path.startswith('rbd:'):
return 'rbd'
return images.qemu_img_info(path).file_format
def get_disk_size(path):
"""Get the (virtual) size of a disk image
:param path: Path to the disk image
:returns: Size (in bytes) of the given disk image as it would be seen
by a virtual machine.
"""
size = images.qemu_img_info(path).virtual_size
return int(size)
def get_disk_backing_file(path, basename=True):
"""Get the backing file of a disk image
:param path: Path to the disk image
:returns: a path to the image's backing store
"""
backing_file = images.qemu_img_info(path).backing_file
if backing_file and basename:
backing_file = os.path.basename(backing_file)
return backing_file
def _get_driver_format(self):
data = images.qemu_img_info(self.path)
return data.file_format or 'raw'
def _get_driver_format(self):
data = images.qemu_img_info(self.path)
return data.file_format or 'raw'