title: Cannot set priority of namenode process xxxxx
body: <p>I'm trying to install hadoop on my mac.</p>
  <p>What I did are</p>
  <pre><code>brew install hadoop 
  *in hadoop-env.sh: set JAVA_HOME and HADOOP_OPTS*
  </code></pre>
  <p>Then, I tried start-dfs.sh, but the following error came up:</p>
  <blockquote>
  <p>AL01299205:hadoop user$ /usr/local/Cellar/hadoop/3.2.1/sbin/start-dfs.sh</p>
  <p>Starting namenodes on [AL01299205.local]</p>
  <p>AL01299205.local: ERROR: Cannot set priority of namenode process 24897</p>
  <p>Starting datanodes Starting secondary namenodes [AL01299205.local]</p>
  <p>AL01299205.local: ERROR: Cannot set priority of secondarynamenode process 25147</p>
  <p>2020-02-19 18:06:08,843 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable</p>
  </blockquote>
  <p>How can I fix this error?</p>