Fair assignment of storage for multiple writers (load balance)
There are multiple solutions to this problem:

Consistent hashing with bounded loads
Generic Bin packing algorithm(Knapsack or other)

Both require that the writer know the free storage amount of the drives.
Consistent hashing with bounded loads is based on the consistent hashing algorithm published by akamai and fixed the issue of load inbalancing by overflowing across the ring to the next free &quot;bin&quot;.