def test_open(tmpdir, fmt):
disk = str(tmpdir.join("disk." + fmt))
qemu_img.create(disk, fmt, size=1024**2)
offset = 64 * 1024
data = b"it works"
with qemu_nbd.open(disk, fmt) as d:
d.write(offset, data)
d.flush()
with qemu_nbd.open(disk, fmt, read_only=True) as d:
assert d.read(offset, len(data)) == data
def test_full_backup_complete_chain(tmpdir, nbd_sock, checkpoint):
depth = 3
chunk_size = 1024**2
disk_size = depth * chunk_size
for i in range(depth):
# Create disk based on previous one.
disk = str(tmpdir.join("disk.{}".format(i)))
if i == 0:
qemu_img.create(disk, "qcow2", size=disk_size)
else:
qemu_img.create(disk, "qcow2", backing="disk.{}".format(i - 1))
# This data can be read only from this disk.
with qemu_nbd.open(disk, "qcow2") as d:
offset = i * chunk_size
d.write(offset, b"%d\n" % offset)
d.flush()
# Start full backup and copy the data, veifying what we read.
with backup.full_backup(tmpdir,
disk,
"qcow2",
nbd_sock,
checkpoint=checkpoint):
verify_full_backup(nbd_sock, "sda")
if checkpoint:
bitmaps = list_bitmaps(disk)
assert len(bitmaps) == 1
assert bitmaps[0]["name"] == checkpoint
def test_full_backup_single_image(tmpdir, user_file, fmt, nbd_sock):
chunk_size = 1024**3
disk_size = 5 * chunk_size
# Create disk
create_image(user_file.path, fmt, disk_size)
# Pupulate disk with data.
with qemu_nbd.open(user_file.path, fmt) as d:
for offset in range(0, disk_size, chunk_size):
d.write(offset, b"%d\n" % offset)
d.flush()
checkpoint = "check1" if fmt == "qcow2" else None
# Start full backup and copy the data, veifying what we read.
with backup.full_backup(tmpdir,
user_file.path,
fmt,
nbd_sock,
checkpoint=checkpoint):
verify_full_backup(nbd_sock, "sda")
if checkpoint:
bitmaps = list_bitmaps(user_file.path)
assert len(bitmaps) == 1
assert bitmaps[0]["name"] == checkpoint
def copy_disk(nbd_url, backup_disk):
log.info("Backing up data extents from %s to %s", nbd_url, backup_disk)
backup_url = urlparse(nbd_url)
with nbd.open(backup_url) as src_client, \
qemu_nbd.open(backup_disk, "qcow2") as dst_client:
nbdutil.copy(src_client, dst_client)
def test_options(tmpdir, fmt, cache, aio, discard):
size = 4 * 1024**2
chunk_size = 128 * 1024
src = str(tmpdir.join("src." + fmt))
qemu_img.create(src, fmt, size=size)
with qemu_nbd.open(src, fmt) as c:
for offset in range(0, size, chunk_size):
c.write(offset, struct.pack(">Q", offset))
c.flush()
dst = str(tmpdir.join("dst." + fmt))
qemu_img.create(dst, fmt, size=size)
src_addr = nbd.UnixAddress(str(tmpdir.join("src.sock")))
dst_addr = nbd.UnixAddress(str(tmpdir.join("dst.sock")))
with qemu_nbd.run(
src, fmt, src_addr,
read_only=True,
cache=cache,
aio=aio,
discard=discard), \
qemu_nbd.run(
dst, fmt, dst_addr,
cache=cache,
aio=aio,
discard=discard), \
nbd.Client(src_addr) as src_client, \
nbd.Client(dst_addr) as dst_client:
nbdutil.copy(src_client, dst_client)
qemu_img.compare(src, dst)
def test_compare_different(tmpdir, src_fmt, dst_fmt):
size = 1024**2
src = str(tmpdir.join("src." + src_fmt))
dst = str(tmpdir.join("dst." + dst_fmt))
qemu_img.create(src, src_fmt, size=size)
qemu_img.create(dst, dst_fmt, size=size)
with qemu_nbd.open(dst, dst_fmt) as c:
c.write(size // 2, b"x")
c.flush()
with pytest.raises(qemu_img.ContentMismatch):
qemu_img.compare(src, dst)
def test_copy_nbd_to_nbd(tmpdir, src_fmt, dst_fmt, zero):
# Make sure we have zero extents larger than MAX_ZERO_SIZE (1 GiB). It
# would be nice to have also data extents larger than MAX_COPY_SIZE (128
# MiB), but this is too slow for automated tests.
size = 2 * io.MAX_ZERO_SIZE
# Default cluser size with qcow2 format.
cluster_size = 64 * 1024
src = str(tmpdir.join("src." + src_fmt))
qemu_img.create(src, src_fmt, size=size)
with qemu_nbd.open(src, src_fmt) as c:
# Create first data extent.
c.write(0, b"data extent 1\n")
# Between the data extents we have a zero extent bigger than
# io.MAX_ZERO_SIZE.
# Create data extent larger than io.BUFFER_SIZE.
data = b"data extent 2\n" + b"x" * io.BUFFER_SIZE
c.write(io.MAX_ZERO_SIZE + 2 * cluster_size, data)
# Between the data extents we have a zero extent smaller than
# io.MAX_ZERO_SIZE.
# Create last data extent at the end of the image.
c.write(size - 4096, b"data extent 3\n")
c.flush()
src_sock = UnixAddress(tmpdir.join("src.sock"))
src_url = urlparse(src_sock.url())
dst = str(tmpdir.join("dst." + dst_fmt))
qemu_img.create(dst, dst_fmt, size=size)
dst_sock = UnixAddress(tmpdir.join("dst.sock"))
dst_url = urlparse(dst_sock.url())
with qemu_nbd.run(src, src_fmt, src_sock, read_only=True), \
qemu_nbd.run(dst, dst_fmt, dst_sock), \
nbd.open(src_url, "r") as src_backend, \
nbd.open(dst_url, "r+") as dst_backend:
# Because we copy to new image, we can alays use zero=False, but we
# test both to verify that the result is the same.
io.copy(src_backend, dst_backend, zero=zero)
qemu_img.compare(src, dst)
def test_full_backup(tmpdir, fmt, transport):
disk_size = 1024**2
disk_part = disk_size // 4
disk = str(tmpdir.join("disk." + fmt))
backup_disk = str(tmpdir.join("backup.raw"))
# Create disk
qemu_img.create(disk, fmt, size=disk_size)
# Pupulate disk with data.
with qemu_nbd.open(disk, fmt) as d:
for i in range(0, disk_size, disk_part):
data = b"%d\n" % i
d.write(i, data.ljust(512))
d.flush()
if transport == "unix":
nbd_sock = nbd.UnixAddress(tmpdir.join("nbd.sock"))
else:
nbd_sock = nbd.TCPAddress("localhost", testutil.random_tcp_port())
# Backup using qemu-img convert.
with backup.full_backup(tmpdir, disk, fmt, nbd_sock):
log.debug("Backing up image with qemu-img")
qemu_img.convert(nbd_sock.url("sda"),
backup_disk,
src_fmt="raw",
dst_fmt="raw",
progress=True)
# Compare source and backup disks.
with qemu_nbd.open(disk, fmt, read_only=True) as d, \
io.open(backup_disk, "rb") as b:
for i in range(0, disk_size, disk_part):
b.seek(i)
assert d.read(i, 512) == b.read(512)
def test_shared(tmpdir, fmt):
size = 1024**2
chunk_size = size // 2
src = str(tmpdir.join("src." + fmt))
qemu_img.create(src, fmt, size=size)
with qemu_nbd.open(src, fmt) as c:
c.write(0, b"a" * chunk_size)
c.write(0, b"b" * chunk_size)
c.flush()
dst = str(tmpdir.join("dst." + fmt))
qemu_img.create(dst, fmt, size=size)
src_addr = nbd.UnixAddress(str(tmpdir.join("src.sock")))
dst_addr = nbd.UnixAddress(str(tmpdir.join("dst.sock")))
# Start 2 qemu-nbd servers, each with 2 clients that can read and write in
# parallel for higher throughput.
with qemu_nbd.run(src, fmt, src_addr, read_only=True, shared=2), \
qemu_nbd.run(dst, fmt, dst_addr, shared=2), \
nbd.Client(src_addr) as src_client1, \
nbd.Client(src_addr) as src_client2, \
nbd.Client(dst_addr) as dst_client1, \
nbd.Client(dst_addr) as dst_client2:
# Copy first half of the image with src_client1 and dst_client2 and
# second half with src_client2 and dst_client2. In a real application
# we would have more clients, running in multiple threads.
chunk1 = src_client1.read(0, chunk_size)
dst_client1.write(0, chunk1)
chunk2 = src_client2.read(chunk_size, chunk_size)
dst_client2.write(chunk_size, chunk2)
dst_client1.flush()
dst_client2.flush()
qemu_img.compare(src, dst)
def copy_dirty(nbd_url, backup_disk):
log.info("Backing up dirty extents from %s to %s", nbd_url, backup_disk)
backup_url = urlparse(nbd_url)
with nbd.open(backup_url, dirty=True) as src_client, \
qemu_nbd.open(backup_disk, "qcow2") as dst_client:
buf = bytearray(4 * 1024**2)
offset = 0
for ext in nbdutil.extents(src_client, dirty=True):
if ext.dirty:
todo = ext.length
while todo:
step = min(todo, len(buf))
view = memoryview(buf)[:step]
src_client.readinto(offset, view)
dst_client.write(offset, view)
offset += step
todo -= step
else:
offset += ext.length