On Tue, 8 Jun 2010, Thomas Mueller wrote: > I would not expect to be the fast (expensive) storage to be that faster > in a ceph cluster. if you get enough cheap storage nodes it will scale > with the amount of disks/nics as the date is striped among all the nodes > (osd's). But this is just my speculation. > > if you have some amount storage nodes and you are on GigE you will hit > the ethernet limit on the client faster than anything else. You can also think of "fast" and "slow" in terms of the ratio of io bandwidth to capacity on each individual device. For example you can use lots of SATA disks in parallel to get more IOPs and throughput, but the platters will be mostly empty. It's often a question of how much total data you have and how much IO to it you need to serve. Of course, there are also absolute performance considerations (SSD read latencies are lower than a disk), so both factors should be considered. sage -- 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
