Hi all. I've read everything in ceph.newdream.net/docs and ceph.newdream.net/wiki. I've also read some articles from ceph.newdream.net/publications. But I haven't found answers on some questions: 1. there is one active MDS and one in standby mode. Active MDS caches all metadata in RAM. Does standby MDS copy this information to RAM? Will it take metadata from OSDs on every request after primary MDS failure? Do read requests come to standby MDS? 2. what replication strategy on OSDs (primary-copy, chain or splay) is turned on by default? 3. when does kernel client understand that the write was successfull (when it recieves ack or commit from primary OSD)? 4. I want to have 3 copies of each object. By default there is a way to write only one successfull copy (and two others give a failure), isn't that? Is there a way to turn this off (even if one of three copies failed, the object will be placed to another PG)? 5. if I have several data centers with good network connection, what is the way to provide data locality? For example, most of write and read requests from Spain come to Spanish DC and most of write and read requests from Russia come to Russian DC. Is it posible? Regards, Vladimir. -- 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
