Mat Eclipse - Java byte 2GB with no GC roots

Question

I am trying to debug large byte object which is 2GB and seems to contain nulls only. I cannot find any GC roots when using Eclipse MAT. The JVM is running IBM J9 in websphere. Any ideas why Eclipse MAT is not showing any GC roots, hard or weak?

Path to GC is showing as the object iteself:

Answer 1

The orange ball on the icon means it is a GC root. The type of root would be shown after the array contents but that isn't visible in the first screenshot. Look in the inspector view when the byte[] array object is selected to find out the type of GC root.