Open Stack

On Mon, Oct 8, 2012 at 8:12 AM, Moritz Krinke <mkrinke at fotocommunity.net> wrote:
> - I cannot change the number of replicas after creating the ring (e.g.
> changing it from 1 to 2)

Not really.  Logically it's not a difficult operation, there's just no
code to do it.  There was a patch a while back, but I guess it wasn't
ever approved:

https://review.openstack.org/#/c/5484/

> - reading about the "unique-as-possible" feature in folsom im asking myself
> how would swift know if nodes are in different places, is there a feature
> like "regions" i am not aware of?

There's no concept of regions (yet).  The commit message is pretty descriptive:

https://github.com/openstack/swift/commit/bb509dd863dc99c06a232d1d8e0f950a7e73dcc8

> - after migration of data and having two replicas spread over those two
> nodes, how can i make sure that in the event of a node beeing down swift
> will not start copying files to second drives on the healty nodes?

Swift won't over-replicate when a node's down, only when an individual
drive is unmounted.  There's no way to disable over-replication in
that case, though.

- Michael