Hello, I have a quick question about the way to layout disks in the OSDs. I can't really find the information I'm looking for on the Wiki or in the existing mailing list archives that I have saved (4-5months worth). In the even a large OSD is being build (say 20 drives, same make/model 2TB). How would you build the OSD? Is it best to format each disk individually or build them into a raid group? Is there performance benefits to having each disk setup individually or perhaps having X amount of raid groups on the system? How would someone theoretically utilize this amount of storage as efficiently as possible? Or am I missing the larger issue and should I be roping all these drives into a btrfs pool? The documentation on disk layout isn't very clear and I'm not quite sure where to head. I'm building out a smallish cluster right now, but I plan on making it quite large in the future. For miscellaneous details assume the following: A 32GB SLC SSD is presented for Journaling Each drive is hot-swappable at the OS and hardware level, and tested The TCP/IP segment is highly bonded (5+ bonds per OSD @ 1G) Network backplane supports max line rates RBD drivers will be used nearly exclusively (minus some S3 gateway usage for minimal storage) Redundancy is of the highest importance, being able to replace a single drive is more important than saving storage Performance is also highly important, however if the tolerance is -/+ 5-10% before it sacrifices redundancy then redundancy would be choosen The ability to build this setup (N+2) and be able to sustain a full OSD failure is also required Knowing this, how would you layout the disks and why? My goal is to basically provision large amounts of media storage to workstations quickly and cheap, which maintaining that the availability of the storage will be higher than the workstation itself. This would include storage of master copies ect ect. PS: Yes I know that Ceph is not a replacement for backups and no solution is perfect, I'm going to use a cluster aware filesystem on the RBD's and mount them also on another machine which will do nightly rsyncs to a drobo. -- Steven Crothers steven.crothers@xxxxxxxxx -- 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
