NAME

       hwloc-gather-topology  - Saves the relevant Linux topology files and the lstopo output for
       later (possibly offline) usage

SYNOPSIS

       hwloc-gather-topology [options] <path>

OPTIONS

       --io   Also gather I/O related files.  The gathering may be much slower, and the generated
              archive  may  be  much  bigger.   --dmi  Also gather DMI/SMBIOS related files.  The
              gathering requires root access, and the dmi-sysfs kernel module should be loaded.

       -h --help
              Display help message and exit

DESCRIPTION

       hwloc-gather-topology  saves  all  the   relevant   topology   files   into   an   archive
       (<path>.tar.bz2)  and  the  lstopo output (<path>.output).  The utility for example stores
       the /proc/cpuinfo file and the entire /sys/devices/system/node/ directory tree.

       These files can be used later to explore the machine topology offline.  Once  the  tarball
       has  been  extracted,  it  may  for instance be given to some hwloc command-line utilities
       through their --input option.  It is also possible to override the default  topology  that
       the  hwloc library will read by setting the extracted path in the HWLOC_FSROOT environment
       variable.

       Both archive and lstopo output may also be submitted to hwloc developers to  debug  issues
       remotely.

       hwloc-gather-topology  is  a  Linux  specific tool, it is not installed on other operating
       systems.

       NOTE: It is highly recommended that you read the hwloc(7)  overview  page  before  reading
       this man page.

EXAMPLES

       To store topology information to be used later (possibly on a different host) please run:

            hwloc-gather-topology /tmp/myhost

       It  will  store  all  relevant  topology  files in the /tmp/myhost.tar.bz2 archive and the
       lstopo output in the /tmp/myhost.output file.  These files can be transferred  on  another
       host for later/offline analysis and/or as the input to various hwloc utilities.

       To use these data with hwloc utilities you have to unpack myhost.tar.bz2 archive first:

            tar jxvf /tmp/myhost.tar.bz2

       A  new directory named myhost now contains all topology files.  Then you ask various hwloc
       utilities to use this topology instead of the one of the real machine by  passing  --input
       myhost.  To display the topology just run:

            lstopo --input ./myhost

       It  is  not necessary that the topology is extracted in the current directory, absolute or
       relative paths are also supported:

            lstopo --input /path/to/remote/host/extracted/topology/

       To see how hwloc would distribute 8 parallel jobs on the original host:

            hwloc-distrib --input myhost --single 8

       To get the corresponding physical indexes in the previous command:

            hwloc-calc  --input  myhost  --po  --li  --proclist  $(hwloc-distrib  --input  myhost
       --single 8)

       Any  program  may actually override the default topology with a given archived one even if
       it does not have a --input option.  The HWLOC_FSROOT environment variable should  be  used
       to do so:

            HWLOC_FSROOT=myhost hwloc-calc --po --li --proclist $(hwloc-distrib --single 8)

       All  these  commands  will  produce the same output as if executed directly on the host on
       which the topology  information  was  originally  gathered  by  the  hwloc-gather-topology
       script.

RETURN VALUE

       Upon successful execution, hwloc-gather-topology will exit with the code 0.

       hwloc-gather-topology will return nonzero exit status if any kind of error occurs, such as
       (but not limited to) failure to create the archive or output file.

SEE ALSO

       hwloc(7), lstopo(1), hwloc-calc(1), hwloc-distrib(1)