Hi Sage, This makes a lot more sense indeed. I updated the http://tracker.ceph.com/issues/5878 description accordingly. ceph osd pool create poolname erasure-code-dir=/var/lib/ceph/erasure-code erasure-code-plugin=jerasure erasure-code-m=10 erasure-code-k=3 erasure-code-algorithm=Reed-Solomon Thanks :-) On 19/08/2013 02:24, Sage Weil wrote: > Hi Loic, > > One other thought on http://tracker.ceph.com/issues/5878: > > The user interface there would let you adjust various parameters of the > pool's erasure coding scheme after the pool is created. As a practical > matter, I suspect that many/most of these fields will be specified exactly > once (at pool creation time) and will be immutable properties of the pool > after that. The m/k at a minimum need to match up with what we are > requesting out of crush. And once there is data stored, I don't think it > will make sense to be able to change the encoding scheme for new objects > and still be able to deal with old objects. (Or maybe it will be, if the > code metadata is in the object_info_t.) > > Even if we do support changing some of these on the fly, though, I suspect > the most important interface, and the first we implement, will be > something like > > ceph osd pool create <name> [key=value ...] > > the various parameters listed, like EC algorithm, m, k, and pg_num. We > can probably generalize the mon command interface to have a key/value list > type that will make this easy to plumb from the CLI (and trivial via > ceph-rest-api). > > sage > -- Loïc Dachary, Artisan Logiciel Libre All that is necessary for the triumph of evil is that good people do nothing.
Attachment:
signature.asc
Description: OpenPGP digital signature
