Hi All, I have 8 servers available to test ceph on which are a bit over powered/under-disked and I'm trying to develop a plan for how to lay out services and how to populate the available disk slots. The hardware is dual socket Intel E5640 chips (8 core total/ node) with 48G RAM, dual 10G ethernet but only four 3.5" SAS slots (with Fusion-MPT controller). Target application is primarily RBD as volume storage backend for openstack (folsom cinder), and possibly using as object store for glance. I'd also like to test CephFS, but don't have a particular usecase in mind for it. The openstack cloud this would back end is used for reasearch computing by a variety of internal research groups and has wildly unpredictable work loads. Volume storage use has not been particularly intensive to date so I don't have a particular performance point to hit. Comparatively the current back end is a single cinder-volume server bpacing volumes on two software raid6 volumes each backed by 12 2T nearline SAS drives. Another option we're evaluating is a Dell EqualLogic san with a mirrored pair of 16x1T drive raid6 units. My first though is to populate the test systesm with a single solid state drive (not sure size or type) to hold the operating system and journals and three 3T SAS drives of the OSD data filesystems. Running 3 osd on all nodes (one per data disk), with mon and mds only on the first 3. My second though is to use 3T drives in all slots. Take the os cut off the top of each (probably 16G each assmbled as software raid10 for 32G or mirrored space) and run 4 osd per node on the remaining disk space using internal journals. Is either more sane than the other? Are both so crazy I should just use an os disk and three osd disks with internal journals? have any better suggestions? Thanks, -Jon -- 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
