I run several proxmox in my lab. Now I want to play with hyper-v and avoid creating virtual mashines from scratch. Can you recommend any tools for raw to vhdx conversion?
You can use built-in qemu-img convert command, it supports vhd, example:
qemu-img convert -f raw -O vpc vdisk.img hyper-v.vhd
For raw>vhdx conversion try Starwind V2V convertor - https://www.starwindsoftware.com/starwind-v2v-converter