pdsh.1 (2012 03)

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pdsh(1) pdsh-2.16 pdsh(1)

(hpux11.31)

NAME

pdsh - issue commands to groups of hosts in parallel

SYNOPSIS

pdsh [options]... command

DESCRIPTION

pdsh is a variant of the rsh(1) command. Unlike rsh(1), which runs commands on a single remote host,

pdsh can run multiple remote commands in parallel. pdsh uses a "sliding window" (or fanout)ofthreads

to conserve resources on the initiating host while allowing some connections to time out. When pdsh

receives SIGINT (ctrl-C), it lists the status of current threads. A second SIGINT within one second ter-

minates the program. Pending threads may be canceled by issuing ctrl-Z within one second of ctrl-C.

Pending threads are those that have not yet been initiated, or are still in the process of connecting to the

remote host.

If a remote command is not speciﬁed on the command line, pdsh runs interactively, prompting for com-

mands and executing them when terminated with a carriage return. In interactive mode, target nodes

that time out on the ﬁrst command are not contacted for subsequent commands, and commands preﬁxed

with an exclamation point will be executed on the local system. The core functionality of pdsh may be

supplemented by dynamically loadable modules. The modules may provide a new connection protocol

(replacing the standard rcmd(3) protocol used by rsh(1)), ﬁltering options (e.g. removing hosts that are

"down" from the target list), and/or host selection options (e.g., -a selects all hosts from a conﬁguration

ﬁle.). By default, pdsh must have at least one "rcmd" module loaded. See the RCMD MODULES section

for more information.

RCMD MODULES

The method by which pdsh runs commands on remote hosts may be selected at runtime using the -R

option (See OPTIONS below). This functionality is ultimately implemented via dynamically loadable

modules, and so the list of available options may be different from installation to installation. A list of

currently available rcmd modules is printed when using any of the -h, -V,or-L options. The default rcmd

module will also be displayed with the -h and -V options.

A list of rcmd modules currently distributed with pdsh follows.

rsh Uses an internal, thread-safe implementation of BSD rcmd(3) to run commands using the

standard rsh(1) protocol.

exec Executes an arbitrary command for each target host. The ﬁrst of the pdsh remote arguments

is the local command to execute, followed by any further arguments. Some simple parameters

are substitued on the command line, including %h for the target hostname, %u for the remote

username, and %n for the remote rank [0-n] (To get a literal % use %%). For example, the fol-

lowing would duplicate using the ssh module to run hostname(1) across the hosts foo[0-10]:

pdsh -R exec -w foo[0-10] ssh -x -l %u %h hostname

and this command line would run grep(1) in parallel across the ﬁles console.foo[0-10]:

pdsh -R exec -w foo[0-10] grep BUG console.%h

ssh Uses a variant of popen(3) to run multiple copies of the ssh(1) command.

mrsh This module uses the mrsh(1) protocol to execute jobs on remote hosts. The mrsh protocol

uses a credential based authentication, forgoing the need to allocate reserved ports. In other

aspects, it acts just like rsh. Remote nodes must be running mrshd(8) in order for the mrsh

module to work.

qsh Allows pdsh to execute MPI jobs over QsNet. Qshell propagates the current working directory,

pdsh environment, and Elan capabilities to the remote process. The following environment

variable are also appended to the environment: RMS_RANK, RMS_NODEID, RMS_PROCID,

RMS_NNODES, and RMS_NPROCS. Since pdsh needs to run setuid root for qshell support,

qshell does not directly support propagation of LD_LIBRARY_PATH and LD_PREOPEN.

Instead the QSHELL_REMOTE_LD_LIBRARY_PATH and

QSHELL_REMOTE_LD_PREOPEN environment variables will may be used and will be

remapped to LD_LIBRARY_PATH and LD_PREOPEN by the qshell daemon if set.

mqsh Similar to qshell, but uses the mrsh protocol instead of the rsh protocol.

HP-UX 11i Version 3: March 2012 − 1 − Hewlett-Packard Company 1

Summary of content (6 pages)

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pdsh(1) pdsh(1) pdsh-2.16 (hpux11.31) NAME pdsh - issue commands to groups of hosts in parallel SYNOPSIS pdsh [options]... command DESCRIPTION pdsh is a variant of the rsh(1) command. Unlike rsh(1), which runs commands on a single remote host, pdsh can run multiple remote commands in parallel. pdsh uses a "sliding window" (or fanout) of threads to conserve resources on the initiating host while allowing some connections to time out.
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pdsh(1) pdsh(1) pdsh-2.16 (hpux11.31) krb4 The krb4 module allows users to execute remote commands after authenticating with kerberos. Of course, the remote rshd daemons must be kerberized. xcpu The xcpu module uses the xcpu service to execute remote commands. OPTIONS The list of available options is determined at runtime by supplementing the list of standard pdsh options with any options provided by loaded rcmd and misc modules.
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pdsh(1) pdsh(1) pdsh-2.16 (hpux11.31) -m block | cyclic Set block versus cyclic allocation of processes to nodes. Default is block. -r railmask Set the rail bitmask for a job on a multirail system. The default railmask is 1, which corresponds to rail 0 only. Each bit set in the argument to -r corresponds to a rail on the system, so a value of 2 would correspond to rail 1 only, and 3 would indicate to use both rail 1 and rail 0. Machines Module Options -a Target all nodes from machines file.
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pdsh(1) pdsh(1) pdsh-2.16 (hpux11.31) rms Module Options The rms module allows pdsh to target nodes based on an RMS resource. The rms module is typically called after all other node selection options, and if no nodes have been selected, the module will examine the RMS_RESOURCEID environment variable and attempt to set the target list of hosts to the nodes in the RMS resource. If an invalid resource is denoted, the variable is silently ignored.
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pdsh(1) pdsh(1) pdsh-2.16 (hpux11.31) DSHPATH If set, the path in DSHPATH will be used as the PATH for the remote processes. FANOUT Set the pdsh fanout (See description of -f above). HOSTLIST EXPRESSIONS As noted in sections above pdsh accepts lists of hosts the general form: prefix[n-m,l-k,...], where n < m and l < k, etc., as an alternative to explicit lists of hosts. This form should not be confused with regular expression character classes (also denoted by ‘‘[]’’).
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(Notes) 6 Hewlett-Packard Company (Notes) −1− HP-UX 11i Version 3: March 2012