On Thu, Apr 11, 2019, 8:53 AM Jason Dillaman <jdillama@xxxxxxxxxx> wrote:
On Thu, Apr 11, 2019 at 8:49 AM Erik McCormick
<emccormick@xxxxxxxxxxxxxxx> wrote:
>
>
>
> On Thu, Apr 11, 2019, 8:39 AM Erik McCormick <emccormick@xxxxxxxxxxxxxxx> wrote:
>>
>>
>>
>> On Thu, Apr 11, 2019, 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.
>>
>>
>> The value of rbd_store_chunk_size in glance is expressed in MB and then converted to mb. I think the default is 8, so you would want 8192 if you're trying to match what the image was uploaded with.
>
>
> Sorry, that should have been "...converted to KB."
Wouldn't it be converted to bytes since all rbd API methods are in bytes? [1]
Well yeah in the end that's true. Old versions I recall just passed a KB number, but now it's
My main point though was just that glance defaults to 8 MB chunks which is nk uch larger than IP was using.self.chunk_size = CONF.rbd_store_chunk_size * 1024 * 1024
>>
>>>
>>> We tried to copy same image in different pool and resulted same
>>> incorrect checksum.
>>>
>>>
>>> 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 = "" - 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
>>> _______________________________________________
>>> ceph-users mailing list
>>> ceph-users@xxxxxxxxxxxxxx
>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
[1] https://github.com/openstack/glance_store/blob/f503633da040a2668f603e4aa34450b7e5db1252/glance_store/_drivers/rbd.py#L301
--
Jason
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