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I have installed an Oracle on my machine. When I open a session with VNCServer and type dbca, either as root or as oracle, I get these errors:

  1. -bash : -dbca : Command Not found
  2. Xlib: connection to ":0.0" refused by server
    Xlib: No protocol specified

What do I need to do to fix this?

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migrated from Apr 26 '13 at 10:33

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run this command as root user [root@localhost]# xhost + then switch to oracle user and try with dbca – user44475 Jul 27 '14 at 9:11

Regarding your first error ('dbca: command not found'):

  • ensure ORACLE_HOME is set correctly
  • ensure $ORACLE_HOME/bin is in your path
  • run the command as oracle user

If the error persists, check the contents and permissions of $ORACLE_HOME/bin.

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This amazing video explains how to solve the error step by step,

If you dont want to watch then follow the text below

1) "Command not found" indicates oracle instance is not running or you have not running the dbca command as oracle user sol: follow @Frank Schmitt answer

2)The No protocol specified error indicates that "the user dont know how to launch UI application" and " user has no permission to lauch UI application" , in this case dbca is a GUI app. sol: as a root run "xhost -" (without quotes)

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