On Tue, Oct 02, 2012 at 01:02:06PM -0700, Gregory Farnum wrote: > Remote and local reservations come out of a different pool? Yes. This simplifies deadlock prevention. > I think I know what you're talking about here, but can you provide a > bit more background on the reservations and stuff? This is an attempt to limit the amount of recovery operations occurring at the same time. Each OSD has a finite number of reservation slots. Reservation requests are made by PGs to the OSD. A reservation request succeeds immedately if there are slots available. If none are available, it will succeed after a reservation is released (freeing a slot). Before a recovery op may proceed, the primary collects reservations from itself and all its replicas. If one of the OSDs is busy, the reservation process will wait until a reservation is available before continuing. -- 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
