On Thu, Apr 11, 2019 at 12:07 AM Brayan Perera <brayan.perera@xxxxxxxxx> wrote:
>
> Dear Jason,
>
>
> Thanks for the reply.
>
> We are using python 2.7.5
>
> Yes. script is based on openstack code.
>
> As suggested, we have tried chunk_size 32 and 64, and both giving same
> incorrect checksum value.
>
> We tried to copy same image in different pool and resulted same
> incorrect checksum.
My best guess is that there is some odd encoding format issues between
the raw byte stream and Python strings. Can you tweak your Python code
to generate a md5sum for each chunk (let's say 4MiB per chunk to match
the object size) and compare that to a 4MiB chunked "md5sum" CLI
results from the associated "rbd export" data file (split -b 4194304
--filter=md5sum). That will allow you to isolate the issue down to a
specific section of the image.
>
> Thanks & Regards,
> Brayan
>
> On Wed, Apr 10, 2019 at 6:21 PM Jason Dillaman <jdillama@xxxxxxxxxx> wrote:
> >
> > On Wed, Apr 10, 2019 at 1:46 AM Brayan Perera <brayan.perera@xxxxxxxxx> 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.
> >
> > What version of Python are you using?
> >
> > > 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'):
> >
> > Am I correct in assuming this was adapted from OpenStack code? That
> > 8-byte "chunk" is going to be terribly inefficient to compute a CRC.
> > Not that it should matter, but does it still fail if you increase this
> > to 32KiB or 64KiB?
> >
> > > 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 !
> > >
> > > --
> > > Best Regards,
> > > Brayan Perera
> > > _______________________________________________
> > > ceph-users mailing list
> > > ceph-users@xxxxxxxxxxxxxx
> > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
> >
> >
> >
> > --
> > Jason
>
>
>
> --
> Best Regards,
> Brayan Perera
--
Jason
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