1sbcast(1)                       Slurm Commands                       sbcast(1)
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NAME

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

10       sbcast [-CfFjpstvV] SOURCE DEST
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DESCRIPTION

14       sbcast  is  used  to transmit a file to all nodes allocated to the cur‐
15       rently active Slurm job.  This command should  only  be  executed  from
16       within  a  Slurm  batch  job  or within the shell spawned after a Slurm
17       job's resource allocation.  SOURCE is the name of a file on the current
18       node.  DEST should be the fully qualified pathname for the file copy to
19       be created on each node.  If a fully qualified  pathname  is  not  pro‐
20       vided,  the  file  will  be  created  in the directory specified in the
21       SbcastParameters parameter in the slurm.conf file (if available) other‐
22       wise it will be created in the current working directory from which the
23       sbcast command is invoked.  DEST should be on a file  system  local  to
24       that  node.  Note that parallel file systems may provide better perfor‐
25       mance than sbcast can provide, although performance will vary  by  file
26       size, degree of parallelism, and network type.
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OPTIONS

30       -C [library], --compress[=library]
31              Compress  the  file  being  transmitted.   The optional argument
32              specifies the data compression library to  be  used.   Supported
33              values are "lz4" (default), "none" and "zlib".  Some compression
34              libraries may be unavailable on some systems.  The default  com‐
35              pression library (and enabling compression itself) may be set in
36              the slurm.conf file using the SbcastParameter option.
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38       -f, --force
39              If the destination file already exists, replace it.
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41       -F number, --fanout=number
42              Specify the fanout of messages used for file transfer.   Maximum
43              value is currently eight.
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45       -j jobID[.stepID], --jobid=jobID[.stepID]
46              Specify  the job ID to use with optional step ID.  If run inside
47              an allocation this is unneeded as the job ID will read from  the
48              environment.
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50       -p, --preserve
51              Preserves  modification  times, access times, and modes from the
52              original file.
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54       -s size, --size=size
55              Specify the block size used for file broadcast.   The  size  can
56              have  a suffix of k or m for kilobytes or megabytes respectively
57              (defaults to bytes).  This size subject to  rounding  and  range
58              limits  to  maintain good performance.  The default value is the
59              file size or 8MB, whichever is smaller.  This value may need  to
60              be set on systems with very limited memory.
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62       -t seconds, --timeout=seconds
63              Specify  the  message  timeout in seconds.  The default value is
64              MessageTimeout as reported by "scontrol show config".  Setting a
65              higher  value may be necessitated by relatively slow I/O perfor‐
66              mance on the compute node disks.
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68       -v, --verbose
69              Provide detailed event logging through program execution.
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71       -V, --version
72              Print version information and exit.
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PERFORMANCE

76       Executing sbcast sends a remote procedure call to slurmctld. If  enough
77       calls  from sbcast or other Slurm client commands that send remote pro‐
78       cedure calls to the slurmctld daemon come in at once, it can result  in
79       a  degradation of performance of the slurmctld daemon, possibly result‐
80       ing in a denial of service.
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82       Do not run sbcast or other Slurm client commands that send remote  pro‐
83       cedure  calls  to  slurmctld  from loops in shell scripts or other pro‐
84       grams. Ensure that programs limit calls to sbcast to the minimum neces‐
85       sary for the information you are trying to gather.
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ENVIRONMENT VARIABLES

89       Some  sbcast options may be set via environment variables.  These envi‐
90       ronment variables, along with their corresponding options,  are  listed
91       below.  (Note:  Command  line  options  will always override these set‐
92       tings.)
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94       SBCAST_COMPRESS     -C, --compress
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96       SBCAST_FANOUT       -F number, --fanout=number
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98       SBCAST_FORCE        -f, --force
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100       SBCAST_PRESERVE     -p, --preserve
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102       SBCAST_SIZE         -s size, --size=size
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104       SBCAST_TIMEOUT      -t seconds, --timeout=seconds
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106       SLURM_CONF          The location of the Slurm configuration file.
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AUTHORIZATION

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

115       Using  a  batch  script, transmit local file my.prog to /tmp/my.proc on
116       the local nodes and then execute it.
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118       > cat my.job
119       #!/bin/bash
120       sbcast my.prog /tmp/my.prog
121       srun /tmp/my.prog
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123       > sbatch --nodes=8 my.job
124       srun: jobid 12345 submitted
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COPYING

128       Copyright (C) 2006-2010 The Regents of the  University  of  California.
129       Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
130       Copyright (C) 2010-2016 SchedMD LLC.
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132       This  file  is  part  of  Slurm,  a  resource  management program.  For
133       details, see <https://slurm.schedmd.com/>.
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135       Slurm is free software; you can redistribute it and/or modify it  under
136       the  terms  of  the GNU General Public License as published by the Free
137       Software Foundation; either version 2  of  the  License,  or  (at  your
138       option) any later version.
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140       Slurm  is  distributed  in the hope that it will be useful, but WITHOUT
141       ANY WARRANTY; without even the implied warranty of  MERCHANTABILITY  or
142       FITNESS  FOR  A PARTICULAR PURPOSE.  See the GNU General Public License
143       for more details.
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SEE ALSO

147       srun(1)
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151April 2020                      Slurm Commands                       sbcast(1)
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