Linux – Virtual infiniband on kvm/qemu or another open source platform

First, create a raw image of the required size. I'll assume 10G is enough. Using seek creates a sparse file, which saves space.

dd if=/dev/null of=example.img bs=1M seek=10240

Next, create a filesystem on it.

mkfs.ext4 -F example.img

(Note that you need the -F option for mkfs.ext4 to operate on a file as opposed to a disk partition)

Then, mount it.

mkdir /mnt/example
mount -t ext4 -o loop example.img /mnt/example

Now you can copy your files to /mnt/example. Once this is done, unmount it and you can use example.img as a drive in a virtual machine. If you want you can convert it from a raw image to another format like qcow2e using qemu-img, but this isn't required.

Most Linux systems use udev to tie an interface name to a specific MAC addresses (so that machines with multiple NICs have the interfaces consistently named across boots). This however causes this problem when the MAC address does change (like when booting in a VM with a different MAC address set) but you don't want a new interface name assigned. To clear these mappings, delete the appropriate file in /etc/udev/rules.d/ (usually named 70-persistent-net.rules) and reboot. In your case you want to do this while creating the master image.