NAME

       sbcast - transmit a file to the nodes allocated to a Slurm job.

SYNOPSIS

       sbcast [-CfFjpstvV] SOURCE DEST

DESCRIPTION

       sbcast  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.  SOURCE is the name of a file on
       the current node.  DEST 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 BcastParameters 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.  DEST should be on a file system local to that node.   Note
       that  parallel  file  systems  may  provide  better  performance  than sbcast can provide,
       although performance will vary by file size, degree of parallelism, and network type.

OPTIONS

       -C, --compress[=library]
              Compress the file being transmitted.  The  optional  argument  specifies  the  data
              compression  library  to be used.  Supported values are "lz4" (default) and "none".
              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 BcastParameters option.

       --exclude=<NONE|path1,...,pathN>
              Comma-separated list of absolute directory paths to be excluded when  autodetecting
              and  broadcasting  executable  shared object dependencies. If the keyword "NONE" is
              configured, no directory paths will be excluded.  The  default  value  is  that  of
              slurm.conf BcastExclude and this option overrides it. See also --send-libs.

       -F, --fanout=<number>
              Specify  the fanout of messages used for file transfer.  Maximum value is currently
              eight.

       -f, --force
              If the destination file already exists, replace it.

       -j, --jobid=<jobID[.stepID]>
              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.

       -p, --preserve
              Preserves modification times, access times, and modes from the original file.

       --send-libs[=yes|no]
              If  set  to  yes (or no argument), autodetect and broadcast the executable's shared
              object dependencies to allocated compute nodes. The files are placed in a directory
              alongside  the  executable.  This  overrides  the  default  behavior  configured in
              slurm.conf SbcastParameters send_libs. See also --exclude.

       -s, --size=<size>
              Specify the block size used for file broadcast.  The size can have a suffix of k or
              m  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.

       -t, --timeout=<seconds>
              Specify the message timeout in seconds.  The default  value  is  MessageTimeout  as
              reported  by "scontrol show config".  Setting a higher value may be necessitated by
              relatively slow I/O performance on the compute node disks.

       -v, --verbose
              Provide detailed event logging through program execution.

       -V, --version
              Print version information and exit.

PERFORMANCE

       Executing sbcast sends a remote procedure call to slurmctld. If enough calls  from  sbcast
       or  other  Slurm  client commands that send remote procedure calls to the slurmctld daemon
       come in at once, it can result in a degradation of performance of  the  slurmctld  daemon,
       possibly resulting in a denial of service.

       Do  not  run  sbcast  or  other  Slurm client commands that send remote procedure calls to
       slurmctld from loops in shell scripts or other programs. Ensure that programs limit  calls
       to sbcast to the minimum necessary for the information you are trying to gather.

ENVIRONMENT VARIABLES

       Some  sbcast  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.)

       SBCAST_COMPRESS     -C, --compress

       SBCAST_EXCLUDE      --exclude=<NONE|path1,...,pathN>

       SBCAST_FANOUT       -F number, --fanout=number

       SBCAST_FORCE        -f, --force

       SBCAST_SEND_LIBS    --send-libs[=yes|no]

       SBCAST_PRESERVE     -p, --preserve

       SBCAST_SIZE         -s size, --size=size

       SBCAST_TIMEOUT      -t seconds, --timeout=seconds

       SLURM_CONF          The location of the Slurm configuration file.

AUTHORIZATION

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

EXAMPLES

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

       $ cat my.job
       #!/bin/bash
       sbcast my.prog /tmp/my.prog
       srun /tmp/my.prog

       $ sbatch --nodes=8 my.job
       srun: jobid 12345 submitted

COPYING

       Copyright (C) 2006-2010 The Regents of the University of California.  Produced at Lawrence
       Livermore National Laboratory (cf, DISCLAIMER).
       Copyright (C) 2010-2021 SchedMD LLC.

       This  file  is  part  of  Slurm,  a  resource  management  program.   For   details,   see
       <https://slurm.schedmd.com/>.

       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.

       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.

SEE ALSO

       srun(1)