Until two minutes ago I had never heard of 'openvms', but a quick search shows me that it support posix, so yes, if you're willing to do the work, go ahead.
Go to Vdbench Downloads and pick up the source code.
Inside you'll find a /Jni directory that contains everything you need.
To start, look for 'make.linux'.
You will need to adjust that script, including a pointer to a java JDK (is there such a thing for openVMS?)
All that basically needs to be done is to compile a small piece of Jni/C code which contains all the OS specific code.
Java class files port 100% across platforms, so basically no need to do any java compiles.
However, Vdbench needs to recognize what platform it is running on so that it can call the proper shared library containing the Jni code.
For that I'll basically need a copy of logfile.html of an attempted Vdbench execution './vdbench -t' usually will be sufficient.
After a successful compile, running ./vdbench -t will tell you if 'everything' works.
However, with a few new systems we have run into problem with inproper translation by Vdbench of the 'openflags=' values passed from Vdbench to the OS during the open() call. Let's not worry about that yet.
One thing you'll find during the Jni compile is that there can be slight differences between what header files are needed, adjust that in the code as needed. You'll also get numerous compiler --warnings--- typically all related to differences how a compiler reacts to typecasting. Ignore all those. In Vdbench I have only tried to get Windows or Solaris compiles to be 100% clean of warnings.
This is a good start, give it a try.
Thanks! It will take us a while.
Will update when we have results.