Methods and systems for allocating disk space and other limited resources (e.g., network bandwidth) for a cluster of data storage nodes using distributed semaphores with atomic updates are described. The distributed semaphores may be built on top of a distributed key-value store and used to reserve disk space, global disk streams for writing data to disks, and per node network bandwidth settings. A distributed semaphore comprising two or more semaphores that are accessed with different keys may be used to reduce contention and allow a globally accessible semaphore to scale as the number of data storage nodes within the cluster increases over time. In some cases, the number of semaphores within the distributed semaphore may be dynamically adjusted over time and may be set based on the total amount of disk space within the cluster and/or the number of contention fails that have occurred to the distributed semaphore.