Ah that explains the crash then.... You can not read the entire physical address space from start to finish because you will hit DMA regions which will cause your reads to activate PCI devices and blue screen the box. You must skip the regions which are reserved to PCI devices. The winpmem device driver allows you to read where ever you want (i.e. it does not protect you from shooting yourself in the foot :-). The user space application is supposed to figure out where its safe to read. From quickly looking at the code for nbdserve https://github.com/jeffbryner/NBDServer/blob/master/main.cpp it does not seem to implement the correct algorithm for skipping the reserved memory regions (it should make an IO control to the pmem driver and ask it). There seems to be some code there to do it but it does not seem complete to me. Maybe best ask the author? Anyway for the purpose of experimenting you could just manually write a short bash script with dd involving the skip and seek parameters to skip over the reserved regions and only image the available regions. This should not crash. If you goal is just to obtain the image over the network, why not use netcat like the example demonstrates? Thanks, Michael. On 15 April 2013 22:34, Ken Pryor <kdpryor(a)gmail.com> wrote: