On Wed, 04/27 13:18, Jason Dillaman wrote: > On Tue, Apr 26, 2016 at 7:20 PM, Fam Zheng <f...@redhat.com> wrote: > > On Tue, 04/26 10:42, Jason Dillaman wrote: > >> On Sun, Apr 24, 2016 at 7:42 PM, Fam Zheng <f...@redhat.com> wrote: > >> > On Fri, 04/22 21:57, Jason Dillaman wrote: > >> >> Since this cannot automatically recover from a crashed QEMU client with > >> >> an > >> >> RBD image, perhaps this RBD locking should not default to enabled. > >> >> Additionally, this will conflict with the "exclusive-lock" feature > >> >> available since the Ceph Hammer-release since both utilize the same > >> >> locking > >> >> construct. > >> >> > >> >> As a quick background, the optional exclusive-lock feature can be > >> >> enabled/disabled on image and safely/automatically handles the case of > >> >> recovery from a crashed client. Under normal conditions, the RBD > >> >> exclusive-lock feature automatically acquires the lock upon the first > >> >> attempt to write to the image and transparently transitions ownership of > >> >> the lock between two or more clients -- used for QEMU live-migration. > >> > > >> > Is it enabled by default? > >> > > >> > >> Starting with the Jewel release of Ceph it is enabled by default. > > > > OK, then I'll leave rbd in this QEMU series for now. > > Without exposing some new API methods, this patch will, unfortunately, > directly conflict with the new Jewel rbd defaults and will actually > result in the image becoming read-only since librbd won't be able to > acquire the exclusive lock when QEMU owns the advisory lock. > > We can probably get the new API methods upstream within a week or two > [1]. If that's too long of a delay, I'd recommend dropping rbd > locking from the series for now.
Yes you are right, I tried to mean "drop" with "leave" :) Thanks, Fam > > [1] http://tracker.ceph.com/issues/15632 > > -- > Jason
