On Mon, Apr 02, 2018 at 10:58:03AM -0700, Gregory Farnum wrote: > Hmm, it sounds like you're interested in extending the RADOS > cache-tier functionality for this. That is definitely a mistake; we > have been backing off support for that over the past several releases. > Sage has a plan for some "tiering v2" infrastructure (that integrates > with SK Telecom's dedupe work) which might fit with this but I don't > think it has any kind of timeline for completion. Varada & others (Danny al-Graf, Dan @ CERN): I was thinking of the intersection of these FlipCart ideas and tiering v2 for RADOS for some of what we discussed at various parts of Cephalocon: At the core of it, it's a bottom-most rung for tiering, that puts just the data of an RADOS object somewhere EXTERNAL to Ceph. The metadata esp OMAP would remain in Ceph. Various thoughts: - External tier might be an extra copy of the data or just the ONLY copy of the data. - Possible external tiers: exports to disk, export to tape, export to another cluster or cloud - RGW: Exposed via S3-Glacier API functions to trigger a copy being brought back from external tier to disk tier. - CephFS: revitalizing the Hierarchal Storage Management calls like IRIS XFS to push data of single files out to external (w/ ioctls to trigger tier transitions). - Both the RGW & CephFS piece need a means to queue & process transitions asynchronously in both directions: - RGW lifecycle says 'this object IS old enough to transition to lower storage class now' - RGW lifecycle doesn't say if the transition has actually happened yet. - RGW needs to be aware of the v2-tiering, and able to do explicit transitions of objects between tiers. -- Robin Hugh Johnson Gentoo Linux: Dev, Infra Lead, Foundation Treasurer E-Mail : robbat2@xxxxxxxxxx GnuPG FP : 11ACBA4F 4778E3F6 E4EDF38E B27B944E 34884E85 GnuPG FP : 7D0B3CEB E9B85B1F 825BCECF EE05E6F6 A48F6136 -- 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
