Dsh

Dsh, short for distributed shell, is a command-line utility that enables administrators to run commands on multiple remote hosts in parallel. It is commonly used for cluster and data-center administration, allowing quick checks, deployments, or diagnostics across many machines.

Dsh operates by reading a host specification from a hostfile or from command-line group definitions. The specification can describe individual hosts or groups, enabling targeted or broad selections. When a command is issued, dsh dispatches it to all selected hosts concurrently, collects standard output and standard error, and presents the results with host labels.

Dsh relies on remote access protocols such as SSH or the older rsh, and uses the authentication method configured in the environment (for example, SSH keys or password prompts). It can merge outputs or keep per-host streams separate, depending on the version and options.

Typical uses include performing system checks, applying updates, or running diagnostics across many machines, enabling faster administration than sequential execution.

As computing environments evolved, dsh has been complemented or replaced in many setups by more feature-rich parallel-SSH frameworks such as pdsh, Ansible, or clusterssh, but it remains in use in some systems for its lightweight, script-friendly interface.