Gluster users - Apr 2021 - Replica bricks fungible?

Are all replica (non-arbiter) bricks identical to each
other? If not, what do they differ in?

What I'm really asking is: can I physically move a brick
from one server to another such as

before              after
node1:brick1        node1:brick1
node2:brick2        node2
node3:brick3        node3:brick3
node4               node4:brick2

and then remove node2 from the volume, add node4 to
it and be back up and running without the need of any
synchronisation?

Il 23/04/21 13:30, Zenon Panoussis ha scritto:
> Are all replica (non-arbiter) bricks identical to each
> other? If not, what do they differ in?
No. At least meta-metadata is different, IIUC.
> What I'm really asking is: can I physically move a brick
> from one server to another such as
[...]
> and then remove node2 from the volume, add node4 to
> it and be back up and running without the need of any
> synchronisation?I'm no expert, but I think you can't. It might be
an interesting
feature, tho. Could be very useful to quickly scale a cluster w/o moving
terabytes of data via network: move some (carefully-chosen) bricks from
old nodes to the new one, replace 'em with empty disks and expand.
Something like MD-RAID metadata.

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Servizi Informatici
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tel.: +39 051 20 95786

> Are all replica (non-arbiter) bricks identical to each
> other? If not, what do they differ in?
> What I'm really asking is: can I physically move a brick
> from one server to another such as
I can now answer my own question: yes, replica bricks are
identical and can be physically moved or copied from one
server to another. I have now done it a few times without
any problems, though I made sure no healing was pending
before the moves.