title: ./runInstaller Oracle 19c - Unable to verify the graphical display setup
body: <p>Problem to install Oracle 19c on CentOS 8.</p>
  <pre><code>[hadoop@localhost dbhome_1]$ sudo ./runInstaller
  [sudo] password for hadoop: 
  ERROR: Unable to verify the graphical display setup. This application requires X display. Make sure that xdpyinfo exist under PATH variable.
  /u01/app/oracle/product/19.0.0/dbhome_1/perl/bin/perl: error while loading shared libraries: libnsl.so.1: cannot open shared object file: No such file or directory
  [hadoop@localhost dbhome_1]$ 
  </code></pre>
  <ul>
  <li>X running?</li>
  </ul>
  <pre><code>[hadoop@localhost dbhome_1]$ ps -e | grep X 
     2171 tty1     00:00:00 Xwayland
     2578 tty2     00:00:22 Xwayland
  </code></pre>
  <ul>
  <li>Can this error occur because I'm using localhost.domain?</li>
  </ul>
  <p>Environmental vars:</p>
  <pre><code>
  # Java 
  export JAVA_HOME=/opt/jdk
  export PATH=$PATH:$JAVA_HOME/bin
  
  # Oracle
  export TMP=/tmp
  export TMPDIR=$TMP
  export ORACLE_HOSTNAME=localhost.localdomain
  export ORACLE_UNQNAME=orcl
  export ORACLE_BASE=/u01/app/oracle
  export ORACLE_HOME=$ORACLE_BASE/product/19.0.0/dbhome_1
  export ORA_INVENTORY=/u01/app/oraInventory
  export ORACLE_SID=orcl
  export DATA_DIR=/u02/oradata
  export PATH=/usr/sbin:/usr/local/bin:$PATH
  export PATH=$ORACLE_HOME/bin:$PATH
  export LD_LIBRARY_PATH=$ORACLE_HOME/lib:/lib:/usr/lib
  export CLASSPATH=$ORACLE_HOME/jlib:$ORACLE_HOME/rdbms/jlib
  </code></pre>
  <ul>
  <li>/etc/hosts file configuration according to ifconfig:</li>
  </ul>
  <pre><code>127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
  ::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
  192.168.15.3 localhost.localdomain
  </code></pre>
  <ul>
  <li>IP adress 192.168.15.3 was extracted from ifconfig:</li>
  </ul>
  <pre><code>[hadoop@localhost dbhome_1]$ ifconfig
  wlo1: flags=4163&lt;UP,BROADCAST,RUNNING,MULTICAST&gt;  mtu 1500
          inet 192.168.15.3  netmask 255.255.255.0  broadcast 192.168.15.255
          inet6 2804:431:c7c0:1c46:10be:3dcc:8f5f:c204  prefixlen 64  scopeid 0x0&lt;global&gt;
          inet6 fe80::afe8:386a:34f:c943  prefixlen 64  scopeid 0x20&lt;link&gt;
          ether a4:63:a1:05:f1:b3  txqueuelen 1000  (Ethernet)
          RX packets 256300  bytes 353610021 (337.2 MiB)
          RX errors 0  dropped 28  overruns 0  frame 0
          TX packets 40392  bytes 5541776 (5.2 MiB)
          TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
  </code></pre>
  <ul>
  <li>Java version:</li>
  </ul>
  <pre><code>[hadoop@localhost dbhome_1]$ java -version
  java version &quot;1.8.0_281&quot;
  Java(TM) SE Runtime Environment (build 1.8.0_281-b09)
  Java HotSpot(TM) 64-Bit Server VM (build 25.281-b09, mixed mode)
  </code></pre>