Which aspect is a significant disadvantage of containers?

Containers use OS-level isolation mechanisms such as Linux namespaces and cgroups to separate workloads, which is a fundamentally weaker boundary than the hardware-level isolation provided by a hypervisor in full virtual machines. A kernel vulnerability or container escape exploit can allow a compromised container to affect sibling containers or the underlying host OS. This shared kernel architecture is the most significant architectural security disadvantage of containers in multi-tenant or untrusted environments.

Faster deployment is actually a key advantage of containers - they start in seconds because they share the host OS kernel and do not need to boot a full guest operating system as VMs do.

Containers are more resource-efficient than VMs because they eliminate the overhead of running a complete guest OS per workload, making inefficiency an incorrect characterization.

Reduced operational overhead is an advantage of containers, not a disadvantage - they simplify application packaging, portability, and deployment pipeline automation.

Containers consume significantly fewer CPU, memory, and storage resources than VMs because they do not require a dedicated OS image per instance, so high resource consumption is not a disadvantage.