Hi, When add osd or remove osd, ceph will backfill to rebalance data. eg: - pg1.0 [1, 2, 3] - add an osd(eg. osd.7) - ceph start backfill, then pg1.0 osd set changes to [1, 2, 7] - if [a, b, c, d, e] are objects needing to backfill to osd.7 and now object a is backfilling - when a write io hits object a, then the io needs to wait for its complete, then goes on. - but if io hits object b which has not been backfilled, io reaches osd.1, then osd.1 send the io to osd.2 and osd.7, but osd.7 does not have object b, so osd.7 needs to wait for object b to backfilled, then write. Is it right? Or osd.1 only send the io to osd.2, not both? -- 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
