[Gluster-users] gluster dispersed volume configuration

[Dimitri Pertin]

Hi Xavier,

Sorry for the delay.
Thanks for you clear and helpful explanation.
This configuration went well, providing the expected result.

Dimitri


On 07/07/2016 11:01, Xavier Hernandez wrote:
> Hi Dimitri,
>
>
> On 06/07/16 18:13, Dimitri Pertin wrote:
>> Hi everyone,
>>
>> I am trying to configure a dispersed volume following this documentation
>> page:
>>
>> http://gluster.readthedocs.io/en/latest/Administrator%20Guide/Setting%20Up%20Volumes/#creating-dispersed-volumes 
>>
>>
>>
>> I have a set of 8 storage nodes, and I want the erasure coding settings
>> to be (k=4)+(r=2). I understood that 6 bricks must be provided in order
>> to create the volume. But my question is: is it possible to exploit the
>> set of 8 servers given this coding configuration? My goal is the
>> following: for each file, a set of 6 servers among the 8 is selected (in
>> a round-robin way for example).
>
> dispersed works with a fixed set of bricks, so you cannot directly do 
> what you want only using disperse. However you can create a 
> distributed-dispersed volume using 6 bricks in each storage node. This 
> way you can create 8 disperse subvolumes, each of them using exactly 6 
> bricks and fully using all 8 storage nodes.
>
> In a "graphical" way:
>
> Storage node:      1 2 3 4 5 6 7 8
> Disperse subvol 1: x x x x x x
> Disperse subvol 2:   x x x x x x
> Disperse subvol 3:     x x x x x x
> Disperse subvol 4: x     x x x x x
> Disperse subvol 5: x x     x x x x
> Disperse subvol 6: x x x     x x x
> Disperse subvol 7: x x x x     x x
> Disperse subvol 8: x x x x x     x
>
> The command line would be something like this:
>
> gluster volume create test disperse 6 redundancy 2 \
>     S1:/B1 S2:/B1 S3:/B1 S4:/B1 S5:/B1 S6:/B1 \
>     S2:/B2 S3:/B2 S4:/B2 S5:/B2 S6:/B2 S7:/B1 \
>     S3:/B3 S4:/B3 S5:/B3 S6:/B3 S7:/B2 S8:/B1 \
>     S4:/B4 S5:/B4 S6:/B4 S7:/B3 S8:/B2 S1:/B2 \
>     S5:/B5 S6:/B5 S7:/B4 S8:/B3 S1:/B3 S2:/B3 \
>     S6:/B6 S7:/B5 S8:/B4 S1:/B4 S2:/B4 S3:/B4 \
>     S7:/B6 S8:/B5 S1:/B5 S2:/B5 S3:/B5 S4:/B5 \
>     S8:/B6 S1:/B6 S2:/B6 S3:/B6 S4:/B6 S5:/B6
>
> Where Sx are the storage servers and Bx are the bricks in each server.
>
> Xavi
>
>>
>> Regards,
>>
>> Dimitri Pertin
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