On Wed, Apr 1, 2015 at 9:49 AM, Sage Weil <sage@xxxxxxxxxxxx> wrote: > 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. Somehow I missed this. I'll take a stab to converting it into a web app. > > sage -- Milosz Tanski CTO 16 East 34th Street, 15th floor New York, NY 10016 p: 646-253-9055 e: milosz@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
