Hi Lindsay, Actually you just setup two entries for each host in your crush map. One for hdd's and one for ssd's. My osd's look like this: # id weight type name up/down reweight -6 1.8 root ssd -7 0.45 host ceph-01-ssd 0 0.45 osd.0 up 1 -8 0.45 host ceph-02-ssd 3 0.45 osd.3 up 1 -9 0.45 host ceph-03-ssd 8 0.45 osd.8 up 1 -10 0.45 host ceph-04-ssd 11 0.45 osd.11 up 1 -1 29.12 root default -2 7.28 host ceph-01 1 3.64 osd.1 up 1 2 3.64 osd.2 up 1 -3 7.28 host ceph-02 5 3.64 osd.5 up 1 4 3.64 osd.4 up 1 -4 7.28 host ceph-03 6 3.64 osd.6 up 1 7 3.64 osd.7 up 1 -5 7.28 host ceph-04 10 3.64 osd.10 up 1 9 3.64 osd.9 up 1 As you can see, I have four hosts: ceph-01 ... ceph-04, but eight host entries. This works great. Regards, Erik. On 30-12-14 15:13, Lindsay Mathieson wrote: > I looked at the section for setting up different pools with different > OSD's (e.g SSD Pool): > > > > http://ceph.com/docs/master/rados/operations/crush-map/#placing-different-pools-on-different-osds > > > > And it seems to make the assumption that the ssd's and platters all live > on separate hosts. > > > > Not the case at all for my setup and I imagine for most people I have > ssd's mixed with platters on the same hosts. > > > > In that case should one have the root buckets referencing buckets not > based on hosts, e.g, something like this: > > > > > > # devices > > # Platters > > device 0 osd.0 > > device 1 osd.1 > > > > # SSD > > device 2 osd.2 > > device 3 osd.3 > > > > host vnb { > > id -2 # do not change unnecessarily > > # weight 1.000 > > alg straw > > hash 0 # rjenkins1 > > item osd.0 weight 1.000 > > item osd.2 weight 1.000 > > } > > host vng { > > id -3 # do not change unnecessarily > > # weight 1.000 > > alg straw > > hash 0 # rjenkins1 > > item osd.1 weight 1.000 > > item osd.3 weight 1.000 > > } > > > > row disk-platter { > > alg straw > > hash 0 # rjenkins1 > > item osd.0 weight 1.000 > > item osd.1 weight 1.000 > > } > > > > row disk-ssd { > > alg straw > > hash 0 # rjenkins1 > > item osd.2 weight 1.000 > > item osd.3 weight 1.000 > > } > > > > > > root default { > > id -1 # do not change unnecessarily > > # weight 2.000 > > alg straw > > hash 0 # rjenkins1 > > item disk-platter weight 2.000 > > } > > > > root ssd { > > id -4 > > alg straw > > hash 0 > > item disk-ssd weight 2.000 > > } > > > > # rules > > rule replicated_ruleset { > > ruleset 0 > > type replicated > > min_size 1 > > max_size 10 > > step take default > > step chooseleaf firstn 0 type host > > step emit > > } > > > > rule ssd { > > ruleset 1 > > type replicated > > min_size 0 > > max_size 4 > > step take ssd > > step chooseleaf firstn 0 type host > > step emit > > } > > > > > > -- > > Lindsay > > > > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com