volcano

A distributed training job is 64 pods that start together or not at all. The deadlock two partially placed jobs produce, counted out on a 64-GPU cluster, and how Kueue and Volcano make the job the unit of admission.

Free GPUs and a pending gang are not a contradiction: the gang needs 64 whole nodes at once and the free GPUs sit on 300 half-used nodes. The isolation order (quota, fit, per-node reasons, one node's device plugin), the command at each step and what it means, and the fixes ranked by displacement.