On Mon, Aug 27, 2012 at 11:50 PM, hemant surale <hemant.surale@xxxxxxxxx> wrote: > Hi All , > I was unable to figure out how we can direct the ceph to store > data based on host needs i.e. Host A wants to keep frequently used > data on its own local OSD. So my question is about how we can direct > such write/read requests to local OSD than on network? Is it possible > ? Due to the nature of CRUSH -- being a deterministic pseudorandom distribution and all -- the writer does not get to choose where n object is stored. The closest thing you can do is have a RADOS pool with a CRUSH ruleset that puts the primary on that machine. As you'd need a pool per machine, this really doesn't scale up well. Perhaps the benefits of the scheme you are envisioning aren't as great as you think they would be. Often accessing lots of fast servers over a fast network performs better than a single local disk. -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html