On Fri, Feb 5, 2016 at 6:24 AM, Mauricio Garavaglia <mauricio@xxxxxxxxxxxx> wrote: > Hello, > > In the January Tech Talk (PostgreSQL on Ceph under Mesos/Aurora with > Docker [https://youtu.be/OqlC7S3cUKs]) we presented a challenge we are > facing at Medallia when running databases on ceph under > mesos/aurora/docker; which is related to prevent mapping/mounting the > same rbd image in two hosts at the same time during network > partitions. > > As a workaround it was mentioned that we are wrapping rbd in a shell > script that executes extra logic around certain operations: > > - On Map; rbd lock add <image> > - If no success; then > - "rbd status <image>": check for Watchers, 3 times each 15 secs > - If found, ABORT the mapping. The image is > still in use in a host that is healthy > - "ceph osd blacklist add <previous lock holder>". > Image locked without a watcher > - steal the lock in <image> > - map the image > > - On Unmap; > - rbd lock remove > > - On reboot of server; > - "ceph osd blacklist rm <self>" > > I was wondering if this mechanism could be incorporated as part of the > rbd CLI, of course controlled by an option during map. We'll be happy > to work on it, but want to check the feasibility of having the patch > accepted. I actually thought we had a disable-by-default config option in later releases that grab the locks before allowing a mount, but now I can't find it. Jason? -Greg -- 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
