[Gluster-users] Replace brick 3.4.2 with 3.6.2?

[John Gardeniers]

Hi All,

We have a gluster volume consisting of a single brick, using replica 2. 
Both nodes are currently running gluster 3.4.2 and I wish to replace one 
of the nodes with a new server (rigel), which has gluster 3.6.2

Following this link:

https://access.redhat.com/documentation/en-US/Red_Hat_Storage/2.1/html/Administration_Guide/Replacing_an_Old_Brick_with_a_New_Brick_on_a_Replicate_or_Distribute-replicate_Volume.html

I tried to do a replace brick but got "volume replace-brick: failed: 
Host rigel is not in 'Peer in Cluster' state". Is this due to a version 
incompatibility or is it due to some other issue? A bit of googling 
reveals the error message in bug reports but I've not yet found anything 
that applies to this specific case.

Incidentally, the clients (RHEV bare metal hypervisors, so we have no 
upgrade option) are running 3.4.0. Will this be a problem if the nodes 
are on 3.6.2?

regards,
John