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  (and  the  destination  library  directory  when  using
              --send-libs) 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.

       SLURM_DEBUG_FLAGS   Specify  debug  flags  for  sbcast  to  use.  See  DebugFlags  in  the
                           slurm.conf(5)  man  page  for  a  full  list of flags. The environment
                           variable takes precedence over the setting in the slurm.conf.

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) 2010-2022 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)