8+2 is recommended for 10 servers. From n+k servers it will be good to choose n with a power of 2(4,8,16,vs) You need to add 10 bricks if you want to extend the volume. On Wed, Sep 21, 2016 at 4:12 PM, Gandalf Corvotempesta <gandalf.corvotempesta@xxxxxxxxx> wrote: > 2016-09-21 14:42 GMT+02:00 Xavier Hernandez <xhernandez@xxxxxxxxxx>: >> You *must* ensure that *all* bricks forming a single disperse set are placed >> in a different server. There are no 4 special fragments. All fragments have >> the same importance. The way to do that is ordering them when the volume is >> created: >> >> gluster volume create test disperse 16 redundancy 4 >> server{1..20}:/bricks/test1 server{1..20}:/bricks/test2 >> server{1..20}:/bricks/test3 >> >> This way all 20 fragments from each disperse set will be placed in a >> different server. However each server will have 3 bricks and no fragment >> from a single file will be stored in more than one brick of each server. > > Now it's clear. > So, at very minimum, EC is good starting from 7+3 (10 servers with 1 > brick each) because: 512*(7-3) = 2048 > Any smaller combinations would mean less redundancy (6+2) or not > optimized stripe size like 512*(5-3)=1024 > > Is this correct ? And what if I have to add some brick to the current > servers or I have to add new servers? > Can I add them freely or I have to follow some rules ? > _______________________________________________ > Gluster-users mailing list > Gluster-users@xxxxxxxxxxx > http://www.gluster.org/mailman/listinfo/gluster-users _______________________________________________ Gluster-users mailing list Gluster-users@xxxxxxxxxxx http://www.gluster.org/mailman/listinfo/gluster-users