What about this example: imagine you have two rooms and want three replicas,
but of course spread over the two rooms. How would you do that with crush? Will
that require to split one room into two virtual rooms (as one would otherwise
end up with 2 replicas only)?
Thanks,
Arne
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Arne Wiebalck
Hey Arne,
So I am not one of the CRUSH-wizards by any means, but while we are
waiting for them I wanted to take a crack at it so you weren't left
hanging. You are able to make more complex choices than just a single
chooseleaf statment in your rules. Take the example from the doc
where you want
Hi Patrick,
We actually already tried that before (get three from racks, then the 4th
from hosts). What we ended up with was a pg that was supposed to go
on the same osd twice … so we rolled back in the end :)
Then we thought it might be better to ask how to do this as the scenario
described
