def estimate_qcow2_size(self, src_vol_params, dst_sd_id):
"""
Calculate volume allocation size for converting raw/qcow2
source volume to qcow2 volume on destination storage domain.
Arguments:
src_vol_params(dict): Dictionary returned from
`storage.volume.Volume.getVolumeParams()`
dst_sd_id(str) : Destination volume storage domain id
Returns:
Volume allocation in bytes
"""
# measure required size.
qemu_measure = qemuimg.measure(image=src_vol_params['path'],
format=sc.fmt2str(
src_vol_params['volFormat']),
output_format=qemuimg.FORMAT.QCOW2)
# Adds extra room so we don't have to extend this disk immediately
# when a vm is started.
chunk_size_mb = config.getint("irs", "volume_utilization_chunk_mb")
chunk_size = chunk_size_mb * MiB
required = (qemu_measure["required"] + chunk_size)
# Limit estimates size by maximum size.
vol_class = sdCache.produce(dst_sd_id).getVolumeClass()
max_size = vol_class.max_size(src_vol_params['capacity'],
sc.COW_FORMAT)
allocation = min(required, max_size)
# Return estimated size of allocation.
self.log.debug("Estimated allocation for qcow2 volume:"
"%d", allocation)
return allocation
def _extend_base_allocation(base_vol, top_vol):
if not (base_vol.is_block() and base_vol.getFormat() == sc.COW_FORMAT):
return
# Measure the subchain from top to base. This gives us the required
# allocation for merging top into base.
log.debug("Measuring sub chain top=%r base=%r", top_vol.volUUID,
base_vol.volUUID)
measure = qemuimg.measure(top_vol.getVolumePath(),
format=qemuimg.FORMAT.QCOW2,
output_format=qemuimg.FORMAT.QCOW2,
is_block=True,
base=base_vol.getVolumePath())
log.debug("Measure result: %s", measure)
# When merging we always copy the bitmaps from the top to base. Measure
# gives us the size of the bitmaps in top *and* base, so this may allocate
# more than needed, but bitmaps are small so it should be good enough.
required_size = measure["required"] + measure.get("bitmaps", 0)
# If the top volume is leaf, the base volume will become leaf after the
# merge, so it needs more space.
optimal_size = base_vol.optimal_cow_size(required_size,
base_vol.getCapacity(),
top_vol.isLeaf())
# Extend the volume.
dom = sdCache.produce(base_vol.sdUUID)
dom.extendVolume(base_vol.volUUID, optimal_size // MiB)
def check_measure(self, filename, compat, format, compressed):
if format != qemuimg.FORMAT.RAW:
filename = convert_to_qcow2(filename, compressed=compressed,
compat=compat)
qemu_info = qemuimg.info(filename)
virtual_size = qemu_info["virtualsize"]
qemu_measure = qemuimg.measure(
filename,
format=format,
output_format=qemuimg.FORMAT.QCOW2)
estimated_size = qemu_measure["required"]
actual_size = converted_size(filename, compat=compat)
error_pct = 100 * float(estimated_size - actual_size) / virtual_size
assert estimated_size >= actual_size
assert error_pct <= 0.1, error_pct
def check_measure(self, filename, compat, format, compressed):
if format != qemuimg.FORMAT.RAW:
filename = convert_to_qcow2(filename, compressed=compressed,
compat=compat)
qemu_info = qemuimg.info(filename)
virtual_size = qemu_info["virtualsize"]
qemu_measure = qemuimg.measure(
filename,
format=format,
output_format=qemuimg.FORMAT.QCOW2)
estimated_size = qemu_measure["required"]
actual_size = converted_size(filename, compat=compat)
error_pct = 100 * float(estimated_size - actual_size) / virtual_size
assert estimated_size >= actual_size
assert error_pct <= 0.1, error_pct
