Hi Xingguo, On Wed, 25 Oct 2017, xie.xingguo@xxxxxxxxxx wrote: > I wonder why erasure-pools can not support omap currently. > > The simplest way for erasure-pools to support omap I can figure out would be duplicating omap on every shard. > > It is because it consumes too much space when k + m gets bigger? Right. There isn't a nontrivial way to actually erasure code it, and duplicating on every shard is inefficient. One reasonableish approach would be to replicate the omap data on m+1 shards. But it's a bit of work to implement and nobody has done it. I can't remember if there were concerns with this approach or it was just a matter of time/resources... Josh? Greg? sage
