Thank you Ramon for your answer. The only thing I can't understand is why to use such a big shard? The default is 64MB. I thought maybe to decrease it, I wanted to do some tests on it.
Best regards, Il giorno ven 6 set 2019 alle ore 23:09 Ramon Selga <[email protected]> ha scritto: > Hi Cristian, > > Both approaches are correct but they have different usable capacity and > tolerance to node failures. > > First one is a full replica 3 meaning you get your total node capacity > divided by 3, because replica 3, and it tolerates a simultaneous of two > nodes and very good for split-brain avoidance. > > Second one is a replica 2 with arbiter, also very good for split-brain > avoidance (that's purpose of arbiter bricks). In this case you get your > total capacity divided by two except a little space going to > arbiter-bricks, may be less than 1% of normal storage bricks. It tolerates > one node failure at the same time. > > For VM usage remember to enable sharding with a shard size of 256MB at > least before use volume. > > If efficiency between total and usable capacity is a concern for you and > you think you could tolerate only one node failure at the same time, may I > suggest you to use a distributed dispersed 3 redundancy 1 volume?. You will > get your total capacity divided by 3 times 2 (that's 2/3 of total capacity) > and this config still tolerates one node failure at the same time. > > Hope this helps. > > *Ramon Selga* > > 934 76 69 10 > 670 25 37 05 > > [image: DataLab SL] <http://www.datalab.es/> > > Aviso Legal <http://www.datalab.es/cont_cas/legal.html> > > > > El 06/09/19 a les 17:11, Cristian Del Carlo ha escrit: > > Hi, > > I have an environment consisting of 4 nodes ( with large disks). > I have to create a volume to contain image of virtual machines. > > In documentation i read: > > > *Hosting virtual machine images requires the consistency of three-way > replication, which is provided by three-way replicated volumes, three-way > distributed replicated volumes, arbitrated replicated volumes, and > distributed arbitrated replicated volumes. * > > So I'm going to confusion to configure this volume. > I have 4 nodes and I don't want to lose space by dedicating one to the > function of arbiter. > > Would it be reasonable to configure the volume as in these two examples? > > # gluster volume create test1 replica 3 \ > server1:/bricks/brick1 server2:/bricks/brick1 server3:/bricks/brick1 \ > server2:/bricks/brick2 server3:/bricks/brick2 server4:/bricks/brick2 \ > server3:/bricks/brick3 server4:/bricks/brick3 server1:/bricks/brick3 \ > server4:/bricks/brick4 server1:/bricks/brick4 server2:/bricks/brick4 > > # gluster volume create test1 replica 3 arbiter 1 \ > server1:/bricks/brick1 server2:/bricks/brick1 > server3:/bricks/arbiter_brick1 \ > server2:/bricks/brick2 server3:/bricks/brick2 > server4:/bricks/arbiter_brick2 \ > server3:/bricks/brick3 server4:/bricks/brick3 > server1:/bricks/arbiter_brick3 \ > server4:/bricks/brick4 server1:/bricks/brick4 > server2:/bricks/arbiter_brick4 > > Thanks, > > -- > > > *Cristian Del Carlo* > > > > _______________________________________________ > Gluster-users mailing > [email protected]https://lists.gluster.org/mailman/listinfo/gluster-users > > > _______________________________________________ > Gluster-users mailing list > [email protected] > https://lists.gluster.org/mailman/listinfo/gluster-users -- *Cristian Del Carlo* *Target Solutions s.r.l.* *T* +39 0583 1905621 *F* +39 0583 1905675 *@* [email protected] http://www.targetsolutions.it P.IVA e C.Fiscale: 01815270465 Reg. Imp. di Lucca Capitale Sociale: €11.000,00 iv - REA n° 173227 Il testo e gli eventuali documenti trasmessi contengono informazioni riservate al destinatario indicato. La seguente e-mail e' confidenziale e la sua riservatezza e' tutelata legalmente dal Decreto Legislativo 196 del 30/06/2003 (Codice di tutela della privacy). La lettura, copia o altro uso non autorizzato o qualsiasi altra azione derivante dalla conoscenza di queste informazioni sono rigorosamente vietate. Qualora abbiate ricevuto questo documento per errore siete cortesemente pregati di darne immediata comunicazione al mittente e di provvedere, immediatamente, alla sua distruzione.
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