Hello Ian, Thanks for your interest. On Mon, Jun 02, 2014 at 06:37:48PM -0400, Ian Colle wrote: > Thanks, Filippos! Very interesting reading. > > Are you comfortable enough yet to remove the RAID-1 from your architecture and > get all that space back? Actually, we are not ready to do that yet. There are three major things to consider. First, to be able to get rid of the RAID-1 setup, we need to increase the replication level to at least 3x. So the space gain is not that great to begin with. Second, this operation can take about a month for our scale according to our calculations and previous experience. During this period of increased I/O we might get peaks of performance degradation. Plus, we currently do not have the necessary hardware available to increase the replication level before we get rid of the RAID setup. Third, we have a few disk failures per month. The RAID-1 setup has allowed us to seamlessly replace them without any hiccup or even a clue to the end user that something went wrong. Surely we can rely on RADOS to avoid any data loss, but if we currently rely on RADOS for recovery there might be some (minor) performance degradation, especially for the VM I/O traffic. Kind Regards, -- Filippos <philipgian@xxxxxxxx> -- 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
