Which background process coordinates the rebalance activity for disk groups?
A. ORBn
B. OSMB
C. RBAL
D. ASMn
RBAL coordinates rebalance activity for a disk group in an ASM instance.
注意:用官方题库到现在发现一直是ASM，把刚看的一个讲解齐全的链接奉上
http://www.jb51.net/article/43527.htm
原文：http://www.cnblogs.com/Babylon/p/7800142.html