Here the output of the console:

    Sep 13 15:15:08 elk systemd[1]: Started Elasticsearch.
    Sep 13 15:15:08 elk systemd[1]: Starting Elasticsearch...
    Sep 13 15:15:11 elk elasticsearch[1617]: Invalid initial heap size: -Xms4g
    Sep 13 15:15:11 elk elasticsearch[1617]: The specified size exceeds the maximum representable size.
    Sep 13 15:15:11 elk elasticsearch[1617]: Error: Could not create the Java Virtual Machine.
    Sep 13 15:15:11 elk systemd[1]: elasticsearch.service: main process exited, code=exited,
    status=1/FAILURE
    Sep 13 15:15:11 elk systemd[1]: Unit elasticsearch.service entered failed state.
    Sep 13 15:15:11 elk systemd[1]: elasticsearch.service failed.

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