NVIDIA Containers & Kubernetes interview questions

Trace sandbox setup, address allocation and a cross-node packet, then distinguish pod reachability from Service translation.

Namespaces partition resources, not trust. This question finds the people who know which sysctls are namespaced, which ones change every tenant at once, and when only a second kernel will do.

Multiple schedulers are supported, rarely understood, and dangerous in a specific way. The strong answer names the deadlock that gang scheduling fixes and the capacity race it can open.

Dockershim is gone and the CRI contract decides what a runtime must do. The senior-level part is the shim model: a supervisor process that owns exit codes and stdio so the daemon can die without taking workloads with it.

Two cleanup mechanisms hide behind one taint: image garbage collection removes unreferenced images by LRU at threshold crossings, while eviction kills pods. Candidates who conflate them fail this question quietly.

Driver, container toolkit, device plugin, DCGM and discovery must version-match on every node. The operator reconciles that ladder from one ClusterPolicy CR; MIG, upgrades and host kernels are where it bites.

Kubernetes does not see GPUs, it sees an extended resource that something has to advertise. When that advertisement is missing or wrong, the scheduler is behaving correctly and the node is lying.

Both run pods, so the answer sounds obvious until an interviewer asks what happens when you delete one. The guarantees are narrower and more specific than most candidates think.

The pair everyone configures and few can explain. QoS hints at eviction risk, but usage versus requests and Pod priority determine node-pressure ranking, and CPU and memory behave completely differently when you exceed them.

A pod is a shared network and storage boundary that happens to contain containers. Once you can say what the containers inside one share, sidecars and init containers stop needing separate explanations.

Service types choose how an application is exposed. Follow the actual traffic path: cloud controllers can target nodes or pods, and internal exposure differs from public exposure.

A Service moves connections and an Ingress reads requests. The gap between those two sentences is hostname routing, path routing and TLS, and it is also why an Ingress object alone does nothing.

Follow a Deployment change through the API server, controllers, scheduler and kubelet. Each handoff gives you a different place to investigate when a pod never starts.

The single most common Kubernetes interview question, and the one where a vague answer is most obvious. Every stage you name is a place the interviewer can ask you to debug.

Everyone can recite the three. Explain what each failure causes, and why a badly configured liveness probe is more dangerous than none at all.

Almost always a finalizer, and the fast fix is the one that loses data. The safe answer explains what the finalizer is protecting against before removing it.

Build instructions depend on earlier inputs, so changing source can invalidate a dependency installation placed after it. Ordering the Dockerfile by how often things change is the whole optimisation, and multi-stage is how the compiler stops shipping to production.

The writable layer is part of the container, not the image, and it dies with the container. Everything about volumes follows from knowing which of those two a file is in.

Evaluate identity, traffic policy and telemetry against measured proxy overhead and operating responsibilities, then test the authorization boundary.

A VM virtualises hardware and boots its own kernel. A container is a process on the host kernel with its view of the world restricted. Everything else, including the security answer, follows from that one difference.

Three states, three completely different causes, and one command that tells you which you are looking at. The state name says whether the problem is the scheduler, the registry or your own process.

A namespace scopes names, permissions and quotas. It does not scope the kernel or the network by default, and the gap between what people assume it isolates and what it does is where the trouble starts.