pdsh(1) General Commands Manual pdsh(1)
pdcp - copy files to groups of hosts in parallel
rpdcp - (reverse pdcp) copy files from a group of hosts in parallel
pdcp [options]... src [src2...] dest
rpdcp [options]... src [src2...] dir
pdcp is a variant of the rcp(1) command. Unlike rcp(1), which copies
files to a single remote host, pdcp can copy files to multiple remote
hosts in parallel. However, pdcp does not recognize files in the for‐
mat ``rname@rhost:path,'' therefore all source files must be on the
local host machine. Destination nodes must be listed on the pdcp com‐
mand line using a suitable target nodelist option (See the OPTIONS sec‐
tion below). Each destination node listed must have pdcp installed for
the copy to succeed.
When pdcp receives SIGINT (ctrl-C), it lists the status of current
threads. A second SIGINT within one second terminates 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.
Like pdsh(1), the functionality of pdcp may be supplemented by dynami‐
cally loadable modules. In pdcp, the modules may provide a new connect
protocol (replacing the standard rsh(1) protocol), filtering options
(e.g. excluding hosts that are down), and/or host selection options
(e.g. -a selects all nodes from a local config file). By default, pdcp
requires at least one "rcmd" module to be loaded (to provide the chan‐
nel for remote copy).
rpdcp performs a reverse parallel copy. Rather than copying files to
remote hosts, files are retrieved from remote hosts and stored locally.
All directories or files retrieved will be stored with their remote
hostname appended to the filename. The destination file must be a
directory when this option is used.
In other respects, rpdcp is exactly like pdcp, and further statements
regarding pdcp in this manual also apply to rpdcp.
The method by which pdcp connects to 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 instal‐
lation. 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 pdcp follows.
rsh Uses an internal, thread-safe implementation of BSD rcmd(3) to
run commands using the standard rsh(1) protocol.
ssh Uses a variant of popen(3) to run multiple copies of the ssh(1)
mrsh This module uses the mrsh(1) protocol to execute jobs on remote
hosts. The mrsh protocol uses a credential based authentica‐
tion, forgoing the need to allocate reserved ports. In other
aspects, it acts just like rsh.
krb4 The krb4 module allows users to execute remote commands after
authenticating with kerberos. Of course, the remote rshd dae‐
mons must be kerberized.
xcpu The xcpu module uses the xcpu service to execute remote com‐
The list of available pdcp options is determined at runtime by supple‐
menting the list of standard pdcp options with any options provided by
loaded rcmd and misc modules. In some cases, options provided by mod‐
ules may conflict with each other. In these cases, the modules are
incompatible and the first module loaded wins.
Target and or filter the specified list of hosts. Do not use
with any other node selection options (e.g. -a, -g, if they are
available). No spaces are allowed in the comma-separated list.
Arguments in the TARGETS list may include normal host names, a
range of hosts in hostlist format (See HOSTLIST EXPRESSIONS), or
a single `-' character to read the list of hosts on stdin.
If a host or hostlist is preceded by a `-' character, this
causes those hosts to be explicitly excluded. If the argument is
preceded by a single `^' character, it is taken to be the path
to file containing a list of hosts, one per line. If the item
begins with a `/' character, it is taken as a regular expres‐
sion on which to filter the list of hosts (a regex argument may
also be optionally trailed by another '/', e.g. /node.*/). A
regex or file name argument may also be preceeded by a minus `-'
to exclude instead of include thoses hosts.
A list of hosts may also be preceded by "user@" to specify a
remote username other than the default, or "rcmd_type:" to spec‐
ify an alternate rcmd connection type for these hosts. When used
together, the rcmd type must be specified first, e.g.
"ssh:user1@host0" would use ssh to connect to host0 as user
Exclude the specified hosts. May be specified in conjunction
with other target node list options such as -a and -g (when
available). Hostlists may also be specified to the -x option
(see the HOSTLIST EXPRESSIONS section below). Arguments to -x
may also be preceeded by the filename (`^') and regex ('/')
characters as described above, in which case the resulting hosts
are excluded as if they had been given to -w and preceeded with
the minus `-' character.
-h Output usage menu and quit. A list of available rcmd modules
will be printed at the end of the usage message.
-q List option values and the target nodelist and exit without
-b Disable ctrl-C status feature so that a single ctrl-C kills par‐
allel copy. (Batch Mode)
-r Copy directories recursively.
-p Preserve modification time and modes.
Explicitly specify path to remote pdcp binary instead of using
the locally executed path. Can also be set via the environment
This option may be used to copy files as another user, subject
to authorization. For BSD rcmd, this means the invoking user and
system must be listed in the user´s .rhosts file (even for
Set the connect timeout. Default is 10 seconds.
Set the maximum number of simultaneous remote copies to number.
The default is 32.
Set rcmd module to name. This option may also be set via the
PDSH_RCMD_TYPE environment variable. A list of available rcmd
modules may be obtained via either the -h or -L options.
When multiple misc modules provide the same options to pdsh, the
first module initialized "wins" and subsequent modules are not
loaded. The -M option allows a list of modules to be specified
that will be force-initialized before all others, in-effect
ensuring that they load without conflict (unless they conflict
with eachother). This option may also be set via the
PDSH_MISC_MODULES environment variable.
-L List info on all loaded pdcp modules and quit.
-d Include more complete thread status when SIGINT is received, and
display connect and command time statistics on stderr when done.
-V Output pdcp version information, along with list of currently
loaded modules, and exit.
As noted in sections above, pdcp accepts ranges of hostnames in 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 con‐
fused with regular expression character classes (also denoted by
``''). For example, foo does not represent foo1 or foo9, but
rather represents a degenerate range: foo19.
This range syntax is meant only as a convenience on clusters with a
prefixNN naming convention and specification of ranges should not be
considered necessary -- the list foo1,foo9 could be specified as such,
or by the range foo[1,9].
Some examples of range usage follow:
Copy /etc/hosts to foo01,foo02,...,foo05
pdcp -w foo[01-05] /etc/hosts /etc
Copy /etc/hosts to foo7,foo9,foo10
pdcp -w foo[7,9-10] /etc/hosts /etc
Copy /etc/hosts to foo0,foo4,foo5
pdcp -w foo[0-5] -x foo[1-3] /etc/hosts /etc
As a reminder to the reader, some shells will interpret brackets ('['
and ']') for pattern matching. Depending on your shell, it may be nec‐
essary to enclose ranged lists within quotes. For example, in tcsh,
the first example above should be executed as:
pdcp -w "foo[01-05]" /etc/hosts /etc
Pdsh/pdcp was originally a rewrite of IBM dsh(1) by Jim Garlick <gar‐
email@example.com> on LLNL's ASCI Blue-Pacific IBM SP system. It is now
also used on Linux clusters at LLNL.
When using ssh for remote execution, stderr of ssh to be folded in with
that of the remote command. When invoked by pdcp, it is not possible
for ssh to prompt for confirmation if a host key changes, prompt for
passwords if RSA keys are not configured properly, etc.. Finally, the
connect timeout is only adjustable with ssh when the underlying ssh
implementation supports it, and pdsh has been built to use the correct