pdsh.1 (2012 03)

pdsh(1) pdsh-2.16 pdsh(1)

(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 ‘‘[]’’). For example, foo[19] does not represent an expression

matching foo1 or foo9, but rather represents the degenerate hostlist: foo19.

The hostlist syntax is meant only as a convenience on clusters with a "preﬁxNNN" naming convention and

speciﬁcation of ranges should not be considered necessary -- this foo1,foo9 could be speciﬁed as such, or

by the hostlist foo[1,9].

Some examples of usage follow:

Run command on foo01,foo02,...,foo05

pdsh -w foo[01-05] command

Run command on foo7,foo9,foo10

pdsh -w foo[7,9-10] command

Run command on foo0,foo4,foo5

pdsh -w foo[0-5] -x foo[1-3] command

A sufﬁx on the hostname is also supported:

Run command on foo0-eth0,foo1-eth0,foo2-eth0,foo3-eth0

pdsh -w foo[0-3]-eth0 command

As a reminder to the reader, some shells will interpret brackets ([ and ]) for pattern matching. Depend-

ing on your shell, it may be necessary to enclose ranged lists within quotes. For example, in tcsh, the

ﬁrst example above should be executed as:

pdsh -w "foo[01-05]" command

ORIGIN

Originally a rewrite of IBM dsh(1) by Jim Garlick <garlick@llnl.gov> on LLNL’s ASCI Blue-Paciﬁc IBM

SP system. It is now used on Linux clusters at LLNL.

LIMITATIONS

When using ssh for remote execution, expect the stderr of ssh to be folded in with that of the remote com-

mand. When invoked by pdsh, it is not possible for ssh to prompt for passwords if RSA/DSA keys are

conﬁgured properly, etc.. For ssh implementations that suppport a connect timeout option, pdsh

attempts to use that option to enforce the timeout (e.g. -oConnectTimeout=T for OpenSSH), otherwise

connect timeouts are not supported when using ssh. Finally, there is no reliable way for pdsh to ensure

that remote commands are actually terminated when using a command timeout. Thus if -u is used with

ssh commands may be left running on remote hosts even after timeout has killed local ssh processes.

Output from multiple processes per node may be interspersed when using qshell or mqshell rcmd

modules.

The number of nodes that pdsh can simultaneously execute remote jobs on is limited by the maximum

number of threads that can be created concurrently, as well as the availability of reserved ports in the rsh

and qshell rcmd modules. On systems that implement Posix threads, the limit is typically deﬁned by the

constant PTHREADS_THREADS_MAX.