Thanks christian.. Got clear about the concept.. thanks very much :) On Tue, Nov 11, 2014 at 5:47 PM, Loic Dachary <l...@dachary.org> wrote:
> Hi Christian, > > On 11/11/2014 13:09, Christian Balzer wrote: > > On Tue, 11 Nov 2014 17:14:49 +0530 Mallikarjun Biradar wrote: > > > >> Hi all > >> > >> When Issued ceph osd dump it displays weight for that osd as 1 and when > >> issued osd tree it displays 0.35 > >> > > > > There are many threads about this, google is your friend. For example: > > https://www.mail-archive.com/ceph-users@lists.ceph.com/msg11010.html > > > > In short, one is the CRUSH weight (usually based on the capacity of the > > OSD), the other is the OSD weight (or reweight in the tree display). > > > > For example think about a cluster with 100 2TB OSDs and you're planning > to > > replace them (bit by bit) with 4TB OSDs. But the hard disks are the same > > speed, so if you would just replace things, more and more data would > > migrate to your bigger OSDs, making the whole cluster actually slower. > > Setting the OSD weight (reweight) to 0.5 for the 4TB OSDs (untiil the > > replacement is complete) will result in them getting the same allocation > as > > the 2TB ones, keeping things even. > > It is a great example. Would you like to add it to > http://ceph.com/docs/giant/rados/operations/control/#osd-subsystem ? If > you do not have time, I volunteer to do it :-) > > Cheers > > > > > Christian > > > >> output from osd dump: > >> { "osd": 20, > >> "uuid": "b2a97a29-1b8a-43e4-a4b0-fd9ee351086e", > >> "up": 1, > >> "in": 1, > >> "weight": "1.000000", > >> "primary_affinity": "1.000000", > >> "last_clean_begin": 0, > >> "last_clean_end": 0, > >> "up_from": 103, > >> "up_thru": 106, > >> "down_at": 0, > >> "lost_at": 0, > >> "public_addr": "10.242.43.116:6820\/27623", > >> "cluster_addr": "10.242.43.116:6821\/27623", > >> "heartbeat_back_addr": "10.242.43.116:6822\/27623", > >> "heartbeat_front_addr": "10.242.43.116:6823\/27623", > >> "state": [ > >> "exists", > >> "up"]}], > >> > >> output from osd tree: > >> # id weight type name up/down reweight > >> -1 7.35 root default > >> -2 2.8 host rack6-storage-5 > >> 0 0.35 osd.0 up 1 > >> 1 0.35 osd.1 up 1 > >> 2 0.35 osd.2 up 1 > >> 3 0.35 osd.3 up 1 > >> 4 0.35 osd.4 up 1 > >> 5 0.35 osd.5 up 1 > >> 6 0.35 osd.6 up 1 > >> 7 0.35 osd.7 up 1 > >> -3 2.8 host rack6-storage-4 > >> 8 0.35 osd.8 up 1 > >> 9 0.35 osd.9 up 1 > >> 10 0.35 osd.10 up 1 > >> 11 0.35 osd.11 up 1 > >> 12 0.35 osd.12 up 1 > >> 13 0.35 osd.13 up 1 > >> 14 0.35 osd.14 up 1 > >> 15 0.35 osd.15 up 1 > >> -4 1.75 host rack6-storage-6 > >> 16 0.35 osd.16 up 1 > >> 17 0.35 osd.17 up 1 > >> 18 0.35 osd.18 up 1 > >> 19 0.35 osd.19 up 1 > >> 20 0.35 osd.20 up 1 > >> > >> Please help me to understand this > >> > >> -regards, > >> Mallikarjun Biradar > > > > > > -- > Loïc Dachary, Artisan Logiciel Libre > > > _______________________________________________ > ceph-users mailing list > ceph-users@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > >
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