On Tue, Apr 24, 2018 at 10:01 AM, Honggang(Joseph) Yang <eagle.rtlinux@xxxxxxxxx> wrote: > hello， > > Could you kindly explain what's the meaning of > CEPH_OSD_ALLOC_HINT_FLAG_IMMUTABLE flag? > > I think it means the corresponding object's data part(not include > attrs) cannot be modified after the initial write. > However, the object can be overwritten by write_full(). The various hint flags enable the OSD to do optimisations based on the expected access pattern -- they're purely advisory and do not enforce anything. If you search for FLAG_IMMUTABLE in the source, you can see that it's used in BlueStore.cc (along with some other flags) to prefer larger chunk sizes. John > > thx, > > Yang Honggang > -- > 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 -- 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
