Xavi will be the better person to clear all your doubts on this feature, however as per my understanding please see the response inline. ~Atin On 11/25/2014 07:11 PM, Ayelet Shemesh wrote: > Hello Gluster experts, > > I have been using gluster for a small cluster for a few years now and I > have a question regarding the new disperse feature, which is for me a much > anticipated addition. > > *Suppose* I create a volume with a disperse set of 3, redundancy 1 (let's > call them A1, A2, A3) and then I add 3 more bricks to that volume (we'll > call them B1, B2, B3). > > *First question* - which of the bricks will be the one carrying the > redundancy data? The current implementation is *non systematic* which means we don't have any dedicated parity/redundancy brick. > > *Second question* - If I have machines with faster disk - should I assign > them to the data or the redundancy bricks? What should I expect the load to > be on the redundancy machine in heavy read scenarios and in heavy write > scenarios? As mentioned above, this configuration is not possible for non systematic implementation. > > *Third question* - *does this require reading the entire data* of A1, A2 > and A3 by initiating a heal or another operation? If the configuration is 2+1 as you mentioned, you can recover the whole set of data from any two of three bricks, the algorithm provides the intelligence of constructing the chunk of data which resides in a brick which might be down for this configuration. > > *4th question* (and most important for me) - I saw in the list that it is > now a Distributed-Dispersed volume. I understand I can now lose, for > example bricks A1 and B1 and still have my entire data intact. Is this also > correct for bricks from the same set, for example A1 and A2? > Or to put it in a more generic way - *does this create the exact same > dispersed volume as if I created it originally with A1, A2 A3 B1 B2 B3 and > a redundancy of 2?* No, if you see the volume info with this configuration it will show you 2 X (2+1) which means on every set the quorum is two i.e. you need to have atleast two bricks running. > > > Many thanks for your work and for your help on this list, > Ayelet > > > > _______________________________________________ > Gluster-users mailing list > Gluster-users@xxxxxxxxxxx > http://supercolony.gluster.org/mailman/listinfo/gluster-users > _______________________________________________ Gluster-users mailing list Gluster-users@xxxxxxxxxxx http://supercolony.gluster.org/mailman/listinfo/gluster-users
