markdown/reference/cli/admin_utilities/hawqssh.html.md.erb

---
title: hawq ssh
---

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Provides SSH access to multiple hosts at once.

## <a id="topic1__section2"></a>Synopsis

``` pre
hawq ssh -f <hostfile_hawqssh>) | (-h <hostname> [-h <hostname> ...]
    [-e]
    [-u <username>]
    [-v]
    [<bash_command>]

hawq ssh [-? | --help]

hawq ssh --version
```

## <a id="topic1__section3"></a>Description

The `hawq ssh` utility allows you to run bash shell commands on multiple hosts at once using SSH (secure shell). You can execute a single command by specifying it on the command-line, or omit the command to enter into an interactive command-line session.

To specify the hosts involved in the SSH session, use the `-f` option to specify a file containing a list of host names, or use the `-h` option to name single host names on the command-line. At least one host name (`-h`) or a host file (`-f`) is required. Note that the current host is ***not*** included in the session by default — to include the local host, you must explicitly declare it in the list of hosts involved in the session.

Before using `hawq ssh`, you must have a trusted host setup between the hosts involved in the SSH session. You can use the utility `hawq ssh-exkeys` to update the known host files and exchange public keys between hosts if you have not done so already.

If you do not specify a command on the command-line, `hawq ssh` will go into interactive mode. At the `hawq ssh` command prompt (`=>`), you can enter a command as you would in a regular bash terminal command-line, and the command will be executed on all hosts involved in the session. To end an interactive session, press `CTRL`+`D` on the keyboard or type `exit` or `quit`.

If a user name is not specified in the host file or via the `-u` option, `hawq ssh` will execute commands as the currently logged in user. To determine the currently logged in user, do a `whoami` command. By default, `hawq ssh` goes to `$HOME` of the session user on the remote hosts after login. To ensure commands are executed correctly on all remote hosts, you should always enter absolute paths.

## <a id="args"></a>Arguments
<dt>-f \<hostfile\_hawqssh\>  </dt>
<dd>Specifies the name of a file that contains a list of hosts that will participate in this SSH session. The host name is required, and you can optionally specify an alternate user name and/or SSH port number per host. The syntax of the host file is one host per line as follows:

``` pre
[username@]hostname[:ssh_port]
```
</dd>

<dt>-h \<hostname\>  </dt>
<dd>Specifies a single host name that will participate in this SSH session. You can use the `-h` option multiple times to specify multiple host names.</dd>


## <a id="topic1__section4"></a>Options

<dt>\<bash\_command\>   </dt>
<dd>A bash shell command to execute on all hosts involved in this session (optionally enclosed in quotes). If not specified, `hawq ssh` will start an interactive session.</dd>

<dt>-e (echo)  </dt>
<dd>Optional. Echoes the commands passed to each host and their resulting output while running in non-interactive mode.</dd>

<dt>-u \<username\>  </dt>
<dd>Specifies the userid for the SSH session.</dd>

<dt>-v (verbose mode)  </dt>
<dd>Reports additional messages in addition to the command output when running in non-interactive mode.</dd>

<dt>-\\\-version  </dt>
<dd>Displays the version of this utility.</dd>

<dt>-?, -\\\-help </dt>
<dd>Displays the online help.</dd>

## <a id="topic1__section5"></a>Examples

Start an interactive group SSH session with all hosts listed in the file `hostfile_hawqssh`:

``` shell
$ hawq ssh -f hostfile_hawqssh
```

At the `hawq ssh` interactive command prompt, run a shell command on all the hosts involved in this session.

``` pre
=> ls -a /data/path-to-masterdd/*
```

Exit an interactive session:

``` pre
=> exit
=> quit
```

Start a non-interactive group SSH session with the hosts named `sdw1` and `sdw2` and pass a file containing several commands named `command_file` to `hawq ssh`:

``` shell
$ hawq ssh -h sdw1 -h sdw2 -v -e < command_file
```

Execute single commands in non-interactive mode on hosts `sdw2` and `localhost`:

``` shell
$ hawq ssh -h sdw2 -h localhost -v -e 'ls -a /data/primary/*'
$ hawq ssh -h sdw2 -h localhost -v -e 'echo $GPHOME'
$ hawq ssh -h sdw2 -h localhost -v -e 'ls -1 | wc -l'
```

## See Also

[hawq ssh-exkeys](hawqssh-exkeys.html#topic1), [hawq scp](hawqscp.html#topic1)