Dear All: I am a complete beginner in Ceph and due to various circumstances I became curious about omap. I made some quick web searches and read some random writings about it, but I still have basic questions.
- If I had to refer to omap in a doc/foo.rst, is there a canonical web-page, blog post, mailing list thread, or a (white)paper that serves to explain what it is? So far the best explanation I found was in ceph-devel archives by Gregory Farnum. - Every casual explanation I found presumes that "an omap" (a set of K/V) is associated with an object. But it is not physically in the object. So, is there a free-standing omap (set of keys)? Or an omap associated with something else, like a pool? - Greg says " The on-disk layout for these is more complicated (read about leveldb if you're interested)". Fair enough... But would someone be willing to shortcut this for me by explaining how this works in concert with OSD. In particular, does OSD replicate the files that LevelDB uses (like, for instance, Swift replicates SQLite files), or does it rely on LevelDB's own replication? Or perhaps OSD replicates upper level view of K/V provided by LevelDB in a node and ignores its actual on-disk layout? Thanks in advance, -- Pete -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
