Re: Review request : Erasure Code plugin loader implementation

[Loic Dachary <loic@dachary.org>]

[-- Attachment #1: Type: text/plain, Size: 1712 bytes --]

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 #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 261 bytes --]