On 05/01/2017 02:25 PM, Gandalf Corvotempesta wrote:> 2017-05-01 20:22 GMT+02:00 Shyam <srangana at redhat.com>:
>> Brick splitting (I think was first proposed by Jeff Darcy) is to create
more
>> bricks out of given storage backends. IOW, instead of using a given
brick as
>> is, create sub-dirs and use them as bricks.
>>
>> Hence, given 2 local FS end points by the user (say), instead of
creating a
>> 1x2 volume, create a nx2 volume, with n sub-dirs within the given local
FS
>> end points as the bricks themselves.
>>
>> Hence, this gives us n units to work with than just one, helping with
issues
>> like +1 scaling, among others.
>
> So, with just one disk, you'll be able to do some replacement like
> Joe's solution
> for adding a single brick regardless the replica count
>
Yes, as a matter of fact, you can do this today using the CLI and
creating nx2 instead of 1x2. 'n' is best decided by you, depending on
the growth potential of your cluster, as at some point 'n' wont be
enough if you grow by some nodes.
But, when a brick is replaced we will fail to address "(a) ability to
retain replication/availability levels" as we support only homogeneous
replication counts across all DHT subvols. (I could be corrected on this
when using replace-brick though)