pssh

Run commands on multiple hosts in parallel

TLDR

Run command on multiple hosts

$ pssh -h [hosts.txt] -i "[uptime]"

Run with inline hosts

$ pssh -H "[user@host1] [user@host2]" -i "[command]"

Run with parallel limit

$ pssh -h [hosts.txt] -p [10] -i "[command]"

Run with timeout

$ pssh -h [hosts.txt] -t [30] -i "[command]"

Copy file to hosts

$ pscp -h [hosts.txt] [local_file] [/remote/path]

Copy file from hosts

$ pslurp -h [hosts.txt] [/remote/file] [local_dir]

Run interactively

$ pssh -h [hosts.txt] -i -A "[sudo command]"

SYNOPSIS

pssh [-h hostfile] [-H hosts] [-p parallel] [-t timeout] [-i] [options] command

pssh (Parallel SSH) runs commands on multiple hosts simultaneously. It parallelizes SSH connections for faster execution across large server fleets.Host files list target machines, one per line. Format supports user@host:port syntax. Comments start with #.Parallel limit controls concurrent connections. Too many simultaneous connections may overwhelm networks or hosts. Start conservatively.Output modes collect results differently. Inline (-i) shows output as it arrives. Directory mode (-o) saves per-host output files.Related tools include pscp for parallel file copy to hosts, pslurp for parallel file retrieval, and prsync for parallel rsync.Timeout prevents hanging on unresponsive hosts. Failed hosts are reported separately from successful ones.

PARAMETERS

-h FILE

File with hosts (one per line).

-H HOSTS

Space-separated hosts.

-l USER

Default username.

-p NUM

Max parallel connections.

-t SECONDS

Timeout per host.

-i, --inline

Display output inline.

-o DIR

Output directory.

-e DIR

Error output directory.

-A

Prompt for password.

-O OPTS

SSH options.

-x ARGS

Extra SSH arguments.

-v

Verbose mode.

INSTALL

sudo dnf install pssh

sudo apk add pssh

sudo zypper install pssh

brew install pssh

nix profile install nixpkgs#pssh

CAVEATS

Requires SSH key auth for non-interactive use. Password prompt (-A) is interactive. Large parallel counts may cause issues. Hostnames must resolve.

HISTORY

pssh was created by Brent N. Chun at Intel Research around 2007. It addressed the need for efficient multi-host command execution in cluster and cloud environments.