Ubuntu Manpage: paralllel-ssh — parallel ssh program

NAME

       paralllel-ssh — parallel ssh program

SYNOPSIS

       paralllel-ssh [-vAiIP] [-h hosts_file] [-H [user@]host[:port]] [-l user] [-p par] [-o outdir] [-e errdir]
       [-t timeout] [-O options] [-x args] [-X arg] command ...

       paralllel-ssh  -I  [-vAiIP]  [-h  hosts_file]  [-H [user@]host[:port]] [-l user] [-p par] [-o outdir] [-e
       errdir] [-t timeout] [-O options] [-x args] [-X arg] [command ...]

DESCRIPTION

       paralllel-ssh is a program for executing ssh in parallel on a number of hosts.  It provides features such
       as sending input to all of the processes, passing a password to ssh, saving output to files,  and  timing
       out.

       The  PSSH_NODENUM  and  PSSH_HOST  environment  variables  are sent to the remote host.  The PSSH_NODENUM
       variable is assigned a unique number for each ssh connection, starting  with  0  and  counting  up.   The
       PSSH_HOST variable is assigned the name of the host as specified in the hosts list.  Note that sshd drops
       environment variables by default, so sshd_config on the remote host must include the line:
              AcceptEnv PSSH_NODENUM PSSH_HOST

OPTIONS

-h host_file
--hosts host_file
Read hosts from the given host_file. Lines in the host file are of the form [user@]host[:port]
and can include blank lines and comments (lines beginning with "#"). If multiple host files are
given (the -h option is used more than once), then paralllel-ssh behaves as though these files
were concatenated together. If a host is specified multiple times, then paralllel-ssh will
connect the given number of times.

-H [user@]host[:port]
--host [user@]host[:port]
-H "[user@]host[:port] [ [user@]host[:port ] ... ]"
--host "[user@]host[:port] [ [user@]host[:port ] ... ]"
Add the given host strings to the list of hosts. This option may be given multiple times, and may
be used in conjunction with the -h option.

-l user
--user user
Use the given username as the default for any host entries that don't specifically specify a user.

-p parallelism
--par parallelism
Use the given number as the maximum number of concurrent connections.

-t timeout
--timeout timeout
Make connections time out after the given number of seconds. With a value of 0, paralllel-ssh
will not timeout any connections.

-o outdir
--outdir outdir
Save standard output to files in the given directory. Filenames are of the form
[user@]host[:port][.num] where the user and port are only included for hosts that explicitly
specify them. The number is a counter that is incremented each time for hosts that are specified
more than once.

-e errdir
--errdir errdir
Save standard error to files in the given directory. Filenames are of the same form as with the
-o option.

-x args
--extra-args args
Passes extra SSH command-line arguments (see the ssh(1) man page for more information about SSH
arguments). This option may be specified multiple times. The arguments are processed to split on
whitespace, protect text within quotes, and escape with backslashes. To pass arguments without
such processing, use the -X option instead.

-X arg
--extra-arg arg
Passes a single SSH command-line argument (see the ssh(1) man page for more information about SSH
arguments). Unlike the -x option, no processing is performed on the argument, including word
splitting. To pass multiple command-line arguments, use the option once for each argument.

-O options
--options options
SSH options in the format used in the SSH configuration file (see the ssh_config(5) man page for
more information). This option may be specified multiple times.

-A
--askpass
Prompt for a password and pass it to ssh. The password may be used for either to unlock a key or
for password authentication. The password is transferred in a fairly secure manner (e.g., it will
not show up in argument lists). However, be aware that a root user on your system could
potentially intercept the password.

-i
--inline
Display standard output and standard error as each host completes.

--inline-stdout
Display standard output (but not standard error) as each host completes.

-v
--verbose
Include error messages from ssh with the -i and \ options.

-I
--send-input
Read input and send to each ssh process. Since ssh allows a command script to be sent on standard
input, the -I option may be used in lieu of the command argument.

-P
--print
Display output as it arrives. This option is of limited usefulness because output from different
hosts are interleaved.

EXAMPLES

       Connect to host1 and host2, and print "hello, world" from each:
              parallel-ssh -i -H "host1 host2" echo "hello, world"

       Print "hello, world" from each host specified in the file hosts.txt:
              parallel-ssh -i -h hosts.txt echo "hello, world"

       Run a command as root with a prompt for the root password:
              parallel-ssh -i -h hosts.txt -A -l root echo hi

       Run a long command without timing out:
              parallel-ssh -i -h hosts.txt -t 0 sleep 10000

       If the file hosts.txt has a large number of entries, say 100, then the parallelism option may also be set
       to 100 to ensure that the commands are run concurrently:
              parallel-ssh -i -h hosts.txt -p 100 -t 0 sleep 10000

       Run a command without checking or saving host keys:
              parallel-ssh -i -H host1 -H host2 -x "-O StrictHostKeyChecking=no -O  UserKnownHostsFile=/dev/null
              -O GlobalKnownHostsFile=/dev/null" echo hi

       Print the node number for each connection (this will print 0, 1, and 2):
              parallel-ssh -i -H host1 -H host1 -H host2 'echo $PSSH_NODENUM'

TIPS

       If  you  have  a  set of hosts that you connect to frequently with specific options, it may be helpful to
       create an alias such as:
              alias pssh_servers="parallel-ssh -h /path/to/server_list.txt -l root -A"

       The ssh_config file can include an arbitrary number of Host sections.   Each  host  entry  specifies  ssh
       options  which  apply  only  to  the  given  host.   Host definitions can even behave like aliases if the
       HostName option is included.  This ssh feature, in combination with parallel-ssh host files,  provides  a
       tremendous amount of flexibility.

EXIT STATUS

       The exit status codes from paralllel-ssh are as follows:

       0      Success

       1      Miscellaneous error

       2      Syntax or usage error

       3      At least one process was killed by a signal or timed out.

       4      All processes completed, but at least one ssh process reported an error (exit status 255).

       5      There were no ssh errors, but at least one remote command had a non-zero exit status.

AUTHORS

       Written by Brent N. Chun <bnc@theether.org> and Andrew McNabb <amcnabb@mcnabbs.org>.

       http://code.google.com/p/parallel-ssh/