2013/1/16 Sage Weil <sage@xxxxxxxxxxx>: > This sort of configuration effectively bundles the disk and SSD into a > single unit, where the failure of either results in the loss of both. > From Ceph's perspective, it doesn't matter if the thing it is sitting on > is a single disk, an SSD+disk flashcache thing, or a big RAID array. All > that changes is the probability of failure. Ok, it will fail, but this should not be an issue, in a cluster like ceph, right? With or without flashcache or SSD, ceph should be able to handle disks/nodes/osds failures on its own by replicating in real time to multiple server. Should I worry about loosing data in case of failure? It should rebalance automatically in case of failure with no data loss. > I would worry that there is a lot of stuff piling onto the SSD and it may > become your bottleneck. My guess is that another 1-2 SSDs will be a > better 'balance', but only experiementation will really tell us that. > > Otherwise, those seem to all be good things to put on teh SSD! I can't add more than 2 SSD, I don't have enough space. I can move OS to the first 2 spinning disks in raid1 software, if this will improve performance of SSD What about swap? I'm thinking to no use swap at all and start with 16/32GB RAM -- 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
