On 12/08/2015 10:44 PM, Alex Gorbachev wrote:
Hi Josh, On Mon, Dec 7, 2015 at 6:50 PM, Josh Durgin <jdurgin@xxxxxxxxxx <mailto:jdurgin@xxxxxxxxxx>> wrote: On 12/07/2015 03:29 PM, Alex Gorbachev wrote: When trying to merge two results of rbd export-diff, the following error occurs: iss@lab2-b1:~$ rbd export-diff --from-snap autosnap120720151500 spin1/scrun1@autosnap120720151502 /data/volume1/scrun1-120720151502.bck iss@lab2-b1:~$ rbd export-diff --from-snap autosnap120720151504 spin1/scrun1@autosnap120720151504 /data/volume1/scrun1-120720151504.bck iss@lab2-b1:~$ rbd merge-diff /data/volume1/scrun1-120720151502.bck /data/volume1/scrun1-120720151504.bck /data/volume1/mrg-scrun1-0204.bck Merging image diff: 11% complete...failed. rbd: merge-diff error That's all the output and I have found this link http://tracker.ceph.com/issues/12911 but not sure if the patch should have already been in hammer or how to get it? That patch fixed a bug that was only present after hammer, due to parallelizing export-diff. You're likely seeing a different (possibly new) issue. Unfortunately there's not much output we can enable for export-diff in hammer. Could you try running the command via gdb to figure out where and why it's failing? Make sure you have librbd-dbg installed, then send the output from gdb doing: gdb --args rbd merge-diff /data/volume1/scrun1-120720151502.bck \ /data/volume1/scrun1-120720151504.bck /data/volume1/mrg-scrun1-0204.bck break rbd.cc:1931 break rbd.cc:1935 break rbd.cc:1967 break rbd.cc:1985 break rbd.cc:1999 break rbd.cc:2008 break rbd.cc:2021 break rbd.cc:2053 break rbd.cc:2098 run # (it will run now, stopping when it hits the error) info locals Will do - how does one load librbd-dbg? I have the following on the system: librbd-dev - RADOS block device client library (development files) librbd1-dbg - debugging symbols for librbd1 is librbd1-dbg sufficient?
Yes, I just forgot the 1 in the package name.
Also a question - the merge-diff really stitches the to diff files together, not really merges, correct? For example, in the following workflow: export-diff from full image - 10GB export-diff from snap1 - 2 GB export-diff from snap2 - 1 GB My resulting merge export file would be 13GB, correct?
It does merge overlapping sections, i.e. part of snap1 that was overwritten in snap2, so the merged diff may be smaller than the original two. Josh _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
