.SH "DESCRIPTION"
\fBsbcast\fR is used to transmit a file to all nodes allocated
to the currently active Slurm job.
This command should only be executed from within a Slurm batch
job or within the shell spawned after a Slurm job's resource
allocation.
\fBSOURCE\fR is the name of a file on the current node.
\fBDEST\fR should be the fully qualified pathname for the
file copy to be created on each node.
If a fully qualified pathname is not provided, the file will be created in
the directory specified in the \fBSbcastParameters\fR parameter in the slurm.conf
file (if available) otherwise it will be created in the current working
directory from which the sbcast command is invoked.
\fBDEST\fR should be on a file system local to that node.
Note that parallel file systems \fImay\fR provide better performance
than \fBsbcast\fR can provide, although performance will vary
by file size, degree of parallelism, and network type.

.SH "OPTIONS"
.TP
\fB\-C\fR [\fIlibrary\fR], \fB\-\-compress\fR[=\fIlibrary\fR]
Compress the file being transmitted.
The optional argument specifies the data compression library to be used.
Supported values are "lz4" (default), "none" and "zlib".
Some compression libraries may be unavailable on some systems.
The default compression library (and enabling compression itself) may be
set in the slurm.conf file using the SbcastParameter option.
.TP
\fB\-f\fR, \fB\-\-force\fR
If the destination file already exists, replace it.
.TP
\fB\-F\fR \fInumber\fR, \fB\-\-fanout\fR=\fInumber\fR
Specify the fanout of messages used for file transfer.
Maximum value is currently eight.
.TP
\fB\-j\fR \fIjobID[.stepID]\fR, \fB\-\-jobid\fR=\fIjobID[.stepID]\fR
Specify the job ID to use with optional step ID.  If run inside an allocation
this is unneeded as the job ID will read from the environment.
.TP
\fB\-p\fR, \fB\-\-preserve\fR
Preserves modification times, access times, and modes from the
original file.
.TP
\fB\-s\fR \fIsize\fR, \fB\-\-size\fR=\fIsize\fR
Specify the block size used for file broadcast.
The size can have a suffix of \fIk\fR or \fIm\fR for kilobytes
or megabytes respectively (defaults to bytes).
This size subject to rounding and range limits to maintain
good performance.
The default value is the file size or 8MB, whichever is smaller.
This value may need to be set on systems with very limited memory.
.SH "PERFORMANCE"
.PP
Executing \fBsbcast\fR sends a remote procedure call to \fBslurmctld\fR. If
enough calls from \fBsbcast\fR or other Slurm client commands that send remote
procedure calls to the \fBslurmctld\fR daemon come in at once, it can result in
a degradation of performance of the \fBslurmctld\fR daemon, possibly resulting
in a denial of service.
.PP
Do not run \fBsbcast\fR or other Slurm client commands that send remote
procedure calls to \fBslurmctld\fR from loops in shell scripts or other
programs. Ensure that programs limit calls to \fBsbcast\fR to the minimum
necessary for the information you are trying to gather.

.SH "ENVIRONMENT VARIABLES"
.PP
Some \fBsbcast\fR options may be set via environment variables.
These environment variables, along with their corresponding options,
are listed below. (Note: Command line options will always override
these settings.)
.TP 20
\fBSBCAST_COMPRESS\fR
\fB\-C, \-\-compress\fR
.TP
\fBSBCAST_FANOUT\fR
\fB\-F\fB \fInumber\fR, \fB\-\-fanout\fR=\fInumber\fR
.TP
\fBSBCAST_FORCE\fR
\fB\-f, \-\-force\fR
.TP
\fBSBCAST_PRESERVE\fR
\fB\-p, \-\-preserve\fR
.TP
\fBSBCAST_SIZE\fR
\fB\-s\fR \fIsize\fR, \fB\-\-size\fR=\fIsize\fR
.TP
\fBSBCAST_TIMEOUT\fR
\fB\-t\fB \fIseconds\fR, \fB\-\-timeout\fR=\fIseconds\fR
.TP
\fBSLURM_CONF\fR
The location of the Slurm configuration file.

.SH "AUTHORIZATION"

When using SlurmDBD, users who have an AdminLevel defined (Operator
or Admin) are given the authority to invoke sbcast on other users jobs.

.SH "EXAMPLE"

Using a batch script, transmit local file \fBmy.prog\fR to
\fB/tmp/my.proc\fR on the local nodes and then execute it.

.nf
.LP
This file is part of Slurm, a resource management program.
For details, see <https://slurm.schedmd.com/>.
.LP
Slurm is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at your option)
any later version.
.LP
Slurm is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
details.

.SH "SEE ALSO"
\fBsrun\fR(1)