How to use dd on WSL? [closed]
This is a category error in usage. dd doesn't work with directories, it works with files. The files can be device files (like /dev/sda or /dev/urandom on Linux), or regular files (like echo foo >> myfile.txt). What you're trying to pass is a directory in a mounted filesystem.
Unfortunately, WSL doesn't seem to support accessing your block device files (i.e. it doesn't have /dev). You can follow this feature request on their issue tracker to see when they will add support.
As @asad-saeeduddin has said, WSL doesn't have block level access, but that doesn't mean that you can't use dd on Windows!
I've found out that dd is part of the set of tools that are installed along with Git for Windows. After install you can find it in C:\Program Files\Git\usr\bin\dd.exe
The Windows equivalent to /dev/sda is \.\PHYSICALDRIVE0 and you can find the proper IDs for your local machine's devices with this command (also returns the sector sizes):
Get-WmiObject Win32_diskdrive | select Caption,DeviceID,BytesPerSector,InterfaceType,Size
The typical usage of the mount command is to specify what you want to mount (a device, on *nix a device is really just a special type of file) and where you want to mount it (a directory). The dd command wants some type of file. In your example, D: is the device, so this is the argument you need to pass to dd:
dd if=D: of=sdDump bs=512 count=1Disclaimer: I do not have WSL experience, but I have been using mount and and dd for decades.