| Hi, list, Ceph cache tier seems very promising for performance. According to http://ceph.com/docs/master/rados/operations/crush-map/#placing-different-pools-on-different-osds , I need to create a new pool based on SSD OSDs。 Currently, I’ve two servers with several HDD-based OSDs. I mean to add one SSD-based OSD for each server, and then use these two OSDs to build a cache pool. But I’ve found problems editing crushmap. The example in the link use two new hosts to build SSD OSDs and then create a new ruleset take the new hosts. But in my environment, I do not have new servers to use. Can I create a ruleset choose part of OSDs in a host? For example, as the crushmap shown below, osd.2 and osd.5 are new added SSD-based OSDs, how can I create a ruleset choose these two OSDs only and how can I avoid default ruleset to choose osd.2 and osd.5? Is this possible, or I have to add a new server to deploy cache tier? Thanks. host node0 { id -2 alg straw hash 0 item osd.0 weight 1.0 # HDD item osd.1 weight 1.0 # HDD item osd.2 weight 0.5 # SSD } host node1 { id -3 alg straw hash 0 item osd.3 weight 1.0 # HDD item osd.4 weight 1.0 # HDD item osd.5 weight 0.5 # SSD } root default { id -1 # do not change unnecessarily # weight 1.560 alg straw hash 0 # rjenkins1 item node0 weight 2.5 item node1 weight 2.5 } # typical ruleset rule replicated_ruleset { ruleset 0 type replicated min_size 1 max_size 10 step take default step chooseleaf firstn 0 type host step emit } |
_______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
