[Gluster-users] Quorum in distributed-replicate volume

[Dave Sherohman]

On Tue, Feb 27, 2018 at 03:20:25PM +0530, Karthik Subrahmanya wrote:
> If you want to use the first two bricks as arbiter, then you need to be
> aware of the following things:
> - Your distribution count will be decreased to 2.

What's the significance of this?  I'm trying to find documentation on
distribution counts in gluster, but my google-fu is failing me.

> - Your data on the first subvol i.e., replica subvol - 1 will be
> unavailable till it is copied to the other subvols
> after removing the bricks from the cluster.

Hmm, ok.  I was sure I had seen a reference at some point to a command
for migrating data off bricks to prepare them for removal.

Is there an easy way to get a list of all files which are present on a
given brick, then, so that I can see which data would be unavailable
during this transfer?

> Since arbiter bricks need not be of same size as the data bricks, if you
> can configure three more arbiter bricks
> based on the guidelines in the doc [1], you can do it live and you will
> have the distribution count also unchanged.

I can probably find one or more machines with a few hundred GB free
which could be allocated for arbiter bricks if it would be sigificantly
simpler and safer than repurposing the existing bricks (and I'm getting
the impression that it probably would be).  Does it particularly matter
whether the arbiters are all on the same node or on three separate
nodes?

-- 
Dave Sherohman