One of my projects recently went to production were getting memory dumps and sever (IM Websphere Portal 6.1) went down intermittently.
To find the root cause, we tried using IBM heap analyzer. But since the files were huge ,400MB it failed to open in IBM Analyzer tools.
As IBM dump files are in PHD (portable heap dump) format most the tools fail to analyze these dumps.
We tried Eclipse Memory Analyzer (MAT) , which also doesn't support IBM .phd file by default.
But there is a IBM Diagnostic Tool Framework for Java ,an (API) used to support the building of Java diagnostics tools.
There is plug-in developed using this API, which can be used along with Eclipse MAT.
Once this plug-in is installed, Eclipse MAT can analyze IBM .phd files.