Which namespace allows for unique host and domain names per process?

The correct answer pertains to the UTS (UNIX Time Sharing) namespace, which is specifically designed to provide unique host and domain names for processes within a Linux environment. This is particularly valuable in containerized or multi-tenant environments where multiple applications or services may be running in isolation but need to maintain distinct hostnames and domain names.

When a process is in the UTS namespace, it can define its own hostname and domain name independently from the host system. This means that if multiple containers (or processes) are running on the same physical or virtual server, each can present itself with a unique hostname and associated domain, avoiding conflicts and enabling more straightforward network interactions.

In contrast, the other namespaces—mount (mnt), process ID (pid), and inter-process communication (ipc)—serve different purposes. The mount namespace isolates the file system views, the PID namespace provides a unique process ID space, and the IPC namespace manages inter-process communication resources. However, none of these namespaces specifically deal with the uniqueness of host and domain names like the UTS namespace does. This makes the UTS namespace essential for managing network identity in containerized environments.