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Home > Success Center > Database Performance Analyzer (DPA) > DPA - Knowledgebase Articles > DPA on a Linux server will not start when /dev/random does not have enough entropy

DPA on a Linux server will not start when /dev/random does not have enough entropy

Updated July 26, 2018

Overview

When DPA is running on a Linux server, it will not start if /dev/random doesn't have enough entropy. This can happen, for example, after you apply the Oracle October 2017 PSU. If this occurs, when you attempt to start DPA, it spins and never starts, even if the REPO.CREATED flag is set to NO.

Environment

  • DPA, all versions
  • Linux server

Cause 

On the DPA server, /dev/random does not have enough entropy to provide output for random number generation used to enable encryption. 

Resolution

Task 1: Determine if lack of entropy is the problem

Run the following command on the DPA server to determine if /dev/random has enough entropy:

cat /dev/random
  • If random output is displayed, lack of entropy is not the problem.
  • If the command is blocked an doesn't print anything, lack of entropy is the problem. Continue with Task 2.

Task 2: Change to /dev/urandom

  1. Shut down DPA (<DPA_HOME>/shutdown.sh).
  2. Open <DPA_HOME>/iwc/jre_linux/lib/security/java.security.
  3. Find: securerandom.source=file:/dev/random.
  4. Change it to: securerandom.source=file:/dev/urandom.
  5. Start DPA (<DPA_HOME>/startup.sh).
 

 

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