Container Resource Failures
Medium Priority24 min readUpdated August 14, 2026
A host may have idle CPU cores and plenty of free memory, yet a container can still become slow or get killed.
That is because containers share the host kernel but operate within their own resource limits. Those limits can be reached even when the host still has capacity.
Different limits also fail in different ways:
- A CPU limit slows work down.
- A memory limit can cause the process to be killed.
- A PID limit can prevent new processes or threads from being created.
- A full writable filesystem can cause writes to fail with
ENOSPC.
Available resources on the host do not guarantee available resources inside a container.
When diagnosing a container issue, always check the resource boundary that applies to that workload.
This chapter compares CPU throttling, memory pressure and cgroup OOM events, PID exhaustion, I/O limits, and full storage, then develops an evidence-driven workflow for identifying the effective boundary before the container disappears.