----- Original Message ----- > From: "Anuradha Talur" <atalur@xxxxxxxxxx> > To: "Gandalf Corvotempesta" <gandalf.corvotempesta@xxxxxxxxx> > Cc: "gluster-users" <Gluster-users@xxxxxxxxxxx> > Sent: Tuesday, July 12, 2016 1:16:00 PM > Subject: Re: Expand distributed replicated volume > > > > ----- Original Message ----- > > From: "Gandalf Corvotempesta" <gandalf.corvotempesta@xxxxxxxxx> > > To: "Anuradha Talur" <atalur@xxxxxxxxxx> > > Cc: "gluster-users" <Gluster-users@xxxxxxxxxxx> > > Sent: Thursday, July 7, 2016 10:14:46 PM > > Subject: Re: Expand distributed replicated volume > > > > Il 07 lug 2016 13:18, "Anuradha Talur" <atalur@xxxxxxxxxx> ha scritto: > > > Node to the cluster? You can add one per time. > > > > > > If you are asking about adding the number of bricks to a volume, > > > in case of replica 3, if you want to keep the replica count same (3) > > > then you have to add 3 bricks. These three bricks will be taken as a > > > new replica group added to the volume. > > > > > > If you want to increase the replica count to 4, then you will have to > > > add one brick each to all the existing replica groups. So that the > > > replica groups now have 4 bricks each. > > > > > > Hope this resolves your query. > > > > Lets assume a 3 nodes cluster, replica 3, 6 1tb disks per node, 1 brick > > per disk. > > > > i would like to increase space and thus add a new node. > > Can i add a single node with 3 disks/bricks and automatically rebalance? > > Yes you can add single node with 3 bricks. But, given that you are keeping > the replica count > same, these three bricks will be replica of each other. It is not so useful > in case of node > failures/shutdown. > > > In this case, gluster moves data around to use the maximum number or disks > > for performance reasons? > > > There are 2 ways to trigger rebalance after adding brick, > 1) without force option : This will not move data. But will add linkto files. > Think of them as symbolic links. Files will reside in the bricks where they > already exist, > but will have links in the new bricks. > 2) With force option : This will actually move the data from old bricks to > new bricks. > > Both these operations will be done only for those files that need to > be migrated. > > The new files will either > 1) be created in new bricks if they hash to new bricks. > or > 2) be created in new bricks even though they hash to old bricks and old > bricks will > have linkto files. > > If there is no space in old bricks to create linkto files too, the operation > will > fail with ENOSPC (no space available). > > I'm cc'ing developers from DHT team in case you have more questions with > respect to > rebalance. Sorry for spam. Forgot to CC. > > We start with 18tb raw, 18 disks, 6tb usable, 100% used (6tb on 6 usable > > disks) > > After adding the new node with 3 disks we will end with 7tb usable. > > all disks would be used as 6tb/7=0.85% right? > > > > -- > Thanks, > Anuradha. > _______________________________________________ > Gluster-users mailing list > Gluster-users@xxxxxxxxxxx > http://www.gluster.org/mailman/listinfo/gluster-users > -- Thanks, Anuradha. _______________________________________________ Gluster-users mailing list Gluster-users@xxxxxxxxxxx http://www.gluster.org/mailman/listinfo/gluster-users
