On Wed, 1 Apr 2015, Milosz Tanski wrote: > On Wed, May 28, 2014 at 10:05 AM, Loic Dachary <loic@xxxxxxxxxxx> wrote: > > > > > > On 28/05/2014 15:35, Koleos Fuskus wrote: > >> > >> > >>> 1. What will be erasure model unit? Is it a pool or a placement group? I cannot see the best option here yet, probably because my inexperience with Ceph. > >> > >> A pool. > >> OK. this is what I thought but some things are not clear enough. I am deploying Ceph to toying a bit more. > >> > >> > >>> 3. Metadata: Jerasure creates metadata files. How are those files stored in ceph (what kind of > >> Jerasure does not create a metadata file. > >> > >> It does on my machine! at least with jerasure 1.2 on mac os :) > > > > If you mean the files that are created by the command line examples provided with jerasure (1.2 or 2), they are not required and only meant for test purposes. > > > > Cheers > > > >> > >> > >> > >> > >> I proposed an update to the documentation to clarify this : https://github.com/ceph/ceph/pull/1856 . Does it look sensible to you ? > >> > >> > > Recently while considering a hardware update on the Ceph cluster I've > been thinking about the durability model of the new OSD nodes once the > cluster is done migrating over. So I came looking through these old > emails. I think it might be very useful to have a web tool that > describes (or visualizes) the current cluster durability model, or > better yet helps you play with the variables to visualize the changes. > > If we can formulate the rules model based on some common variables > (about machines, OSDs, racks) and replication rules (count or erasure > coding paramaters). Then we can spit out useful information like: > - How many nodes / racks / osds do you need to lose to have data offline > - What percentage of data is going to be unavailable if you lose X resources > - What's the probability of data loss over time > - How does the readability model impact your cluster network traffic, > repair traffic > > I think it would be stair-forward to build the web app. In fact, I'll > volunteer myself for that task. Before we start that I would suggest > we try to get the model in something like Google Docs Sheets so we can > use it as a basis. If can you haven't seen this: https://github.com/ceph/ceph-tools/tree/master/models/reliability It's not web-based but it probably could be changed to be. I definitely like the idea of having a hosted version. sage -- 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
