QNX Image for VMware

Hi

I try to set up a QNX image with Momentics System Builder for VmWare
(Windows Host).

What I have so far:
I have made an IFS image with all the stuff I need, called .altboot. I
copy this to an existing and working VmWare image of QNX. Then I
restart, press ESC to boot from altboot and my image is loaded.

So far, so good.
However I have a question:

I have not found information, how I can use an EFS image with VmWare.
On our ‘real’ targets we have flash memory to store the EFS, but can
I do it also on VmWare? Maybe with a RAM disk?