On 06/06/2014 10:14 AM, zou wonder wrote:
Hi buddies, I am doing investigation on Ceph and Swift,and I am newbie to Ceph. I am unclear to the behaviour of the Ceph when there is overload situation. According to the doc, when Ceph do CRUSH, if it find the OSD is overload, it will skip it to select the other OSD. It means if the OSD don't get overloaded the object should be put in this OSD. So how about the original on put on this OSD when it is not get overloaded? Can we read it ? When doing CRUSH , the OSD will be skip.
CRUSH will not take any performance characteristics into account. If a OSD is 100% utilized it will still be selected by CRUSH.
Keep in mind however that Block Devices are striped in 4MB chunks and the same happens for Objects stored via the RADOS Gateway.
If my understanding is wrong, please correct me. Best Regards, zou -- 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
-- Wido den Hollander 42on B.V. Ceph trainer and consultant Phone: +31 (0)20 700 9902 Skype: contact42on -- 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
