On 06/26/2013 11:15 AM, Josh Durgin wrote:
On 06/26/2013 05:40 AM, Karol Jurak wrote:
Hi,
I'm using ceph 0.56.6 and kernel 3.9.7 and it looks like modifying RBD
image
also changes it's snapshot. I can reproduce this as follows:
# create and map an image
rbd create --size 128 test-1
rbd map test-1
# write some data to the image
dd if=/dev/zero of=/dev/rbd/rbd/test-1 bs=1M count=128
# create and map a snapshot
rbd snap create test-1@snap-1
rbd map test-1@snap-1
# verify that image and snapshot are identical
md5sum /dev/rbd/rbd/test-1 /dev/rbd/rbd/test-1@snap-1
fde9e0818281836e4fc0edfede2b8762 /dev/rbd/rbd/test-1
fde9e0818281836e4fc0edfede2b8762 /dev/rbd/rbd/test-1@snap-1
# modify the image
dd if=/dev/urandom of=/dev/rbd/rbd/test-1 bs=512 count=1
# compare checksums again
md5sum /dev/rbd/rbd/test-1 /dev/rbd/rbd/test-1@snap-1
1d942c8a5bc7480cecb945ea0d020eed /dev/rbd/rbd/test-1
1d942c8a5bc7480cecb945ea0d020eed /dev/rbd/rbd/test-1@snap-1
Checksums are identical although the snapshot isn't supposed to be
modified.
Just reproduced on 3.10-rc7 as well. It seems the snapshot context
loading is broken for format 1 a t least, since unmapping and mapping
after the snapshot exists still has the same problem. I added
http://tracker.ceph.com/issues/5464 to track this.
Apparently the regression test for this hasn't been running, or we
would've caught this sooner.
There's a fix for this on the stable kernel in the wip-snapc-3.9.y
branch of ceph-client.git.
Josh
--
To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
