On 10/04/2019 07:46, Brayan Perera wrote:
Dear All,
Ceph Version : 12.2.5-2.ge988fb6.el7
We are facing an issue on glance which have backend set to ceph, when
we try to create an instance or volume out of an image, it throws
checksum error.
When we use rbd export and use md5sum, value is matching with glance checksum.
When we use following script, it provides same error checksum as glance.
We have used below images for testing.
1. Failing image (checksum mismatch): ffed4088-74e1-4f22-86cb-35e7e97c377c
2. Passing image (checksum identical): c048f0f9-973d-4285-9397-939251c80a84
Output from storage node:
1. Failing image: ffed4088-74e1-4f22-86cb-35e7e97c377c
checksum from glance database: 34da2198ec7941174349712c6d2096d8
[root@storage01moc ~]# python test_rbd_format.py
ffed4088-74e1-4f22-86cb-35e7e97c377c admin
Image size: 681181184
checksum from ceph: b82d85ae5160a7b74f52be6b5871f596
Remarks: checksum is different
2. Passing image: c048f0f9-973d-4285-9397-939251c80a84
checksum from glance database: 4f977f748c9ac2989cff32732ef740ed
[root@storage01moc ~]# python test_rbd_format.py
c048f0f9-973d-4285-9397-939251c80a84 admin
Image size: 1411121152
checksum from ceph: 4f977f748c9ac2989cff32732ef740ed
Remarks: checksum is identical
Wondering whether this issue is from ceph python libs or from ceph itself.
Please note that we do not have ceph pool tiering configured.
Please let us know whether anyone faced similar issue and any fixes for this.
test_rbd_format.py
===================================================
import rados, sys, rbd
image_id = sys.argv[1]
try:
rados_id = sys.argv[2]
except:
rados_id = 'openstack'
class ImageIterator(object):
"""
Reads data from an RBD image, one chunk at a time.
"""
def __init__(self, conn, pool, name, snapshot, store, chunk_size='8'):
self.pool = pool
self.conn = conn
self.name = name
self.snapshot = snapshot
self.chunk_size = chunk_size
self.store = store
def __iter__(self):
try:
with conn.open_ioctx(self.pool) as ioctx:
with rbd.Image(ioctx, self.name,
snapshot=self.snapshot) as image:
img_info = image.stat()
size = img_info['size']
bytes_left = size
while bytes_left > 0:
length = min(self.chunk_size, bytes_left)
data = image.read(size - bytes_left, length)
bytes_left -= len(data)
yield data
raise StopIteration()
except rbd.ImageNotFound:
raise exceptions.NotFound(
_('RBD image %s does not exist') % self.name)
conn = rados.Rados(conffile='/etc/ceph/ceph.conf',rados_id=rados_id)
conn.connect()
with conn.open_ioctx('images') as ioctx:
try:
with rbd.Image(ioctx, image_id,
snapshot='snap') as image:
img_info = image.stat()
print "Image size: %s " % img_info['size']
iter, size = (ImageIterator(conn, 'images', image_id,
'snap', 'rbd'), img_info['size'])
import six, hashlib
md5sum = hashlib.md5()
for chunk in iter:
if isinstance(chunk, six.string_types):
chunk = six.b(chunk)
md5sum.update(chunk)
md5sum = md5sum.hexdigest()
print "checksum from ceph: " + md5sum
except:
raise
===================================================
Thank You !
some comments
1) the code:
if isinstance(chunk, six.string_types):
chunk = six.b(chunk)
are there cases where the if will/will-not occur ? does six.b() do any
encoding ?
2) can you adapt the script to calculate the checksum direct from the
export file created by rbd export rather than reading the data directly
itself, does it make a difference ?
3) the image sizes are not multiple of 1M which is a bit strange
4) you using rbd -export-format 1 (default) correct ?
/Maged
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