If you've previously set manual overrides to MaxPermSize options in your configurations, you can remove them away safely having switched to using JDK8. If you still have parts that use JDK7, leave them be and ignore the warning. The warnings themselves do not pose a problem, as JDK8 will simply note that it won't be using them anymore and continue to start up normally. However, a future Java version (JDK9 or 10) may choose to interpret it as an invalid command and fail. Read more on this JDK level change at https://dzone.com/articles/java-8-permgen-metaspace ... View more