Provided by: pssh_2.3.5-2_all bug

NAME

       parallel-ssh — parallel ssh program

SYNOPSIS

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

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

DESCRIPTION

       parallel-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, PSSH_NUMNODES, 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_NUMNODES variable is assigned the total  number
       of  node  being used. 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_NUMNODES 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 parallel-ssh behaves as though these files were concatenated together.   If  a
              host  is  specified multiple times, then parallel-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.

       -g pattern
       --host-glob pattern
              Filter  hosts with glob pattern pattern.  This uses the same syntax as shell globs.
              Make sure to quote the pattern to prevent shell from  expanding  it.  Examples  are
              "*web*" and "company_*".

       -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,
              parallel-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 -e 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 parallel-ssh_servers="parallel-ssh -h /path/to/server_list.txt -l root -A"

       Note  that  when  an ssh command is terminated, it does not kill remote processes (OpenSSH
       bug #396 has been open since 2002).  One workaround is  to  instruct  ssh  to  allocate  a
       pseudo-terminal,  which makes it behave more like a normal interactive ssh session.  To do
       this, use parallel-ssh's "-x" option to pass "-tt" to ssh.  For example:
              parallel-ssh -i -x "-tt" -h hosts.txt -t 10 sleep 1000
       will ensure that all of the sleep commands will  terminate  (with  SIGHUP)  after  the  10
       second timeout.

       By  default,  ssh uses full buffering for non-interactive commands.  Line buffering may be
       preferable to full buffering if you intend to look at the files in an output directory  as
       a  command  is  running.  To switch ssh to use line buffering, use its "-tt" option (which
       allocates a pseudo-terminal) using the "-x" option in parallel-ssh.

       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 parallel-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>.

       https://github.com/lilydjwg/parallel-ssh

SEE ALSO

       ssh(1),  ssh_config(5),  parallel-scp(1),  parallel-rsync(1), parallel-slurp(1), parallel-
       nuke(1),

                                         January 24, 2012                         parallel-ssh(1)