UFS Installing a new operating system using DD


I've tried using FreeBSD but due to a lot of unsupported software and a few strange interactions with my CPU I simply wish to install another operating system. On Linux this would be easy, just use 'dd if=myiso.iso of=/dev/sdb (my ssd partition)'. However, when I tried to do this on FreeBSD, I got an 'operation not permitted' error.

I attempted to run it using this command: 'dd if=/root/Downloads/myiso.iso of=/dev/ada1', where I used ada1 assuming it was my SSD.

How can I achieve what I'm trying to do on FreeBSD? Yes I understand that using a USB is the easiest option but it was a perfectly viable option on Linux, and I don't see why that would change on FreeBSD.


Staff member
FreeBSD protects the boot sector of the boot disk against accidental overwriting. It simply prevents you from shooting yourself in the foot.

sysctl kern.geom.debugflags=16
With dd(1) you're transfering all data of the source device, including metadata describing the filesystem. Usually, on an .iso there's an ISO-9660 filesystem, whereas on a HDD/SSD other filesystems are expected. For FreeBSD these are usually UFS & ZFS. Thus, if you want to "transfer" an OS from an ISO image to your HDD/SSD, use the installer. It does some more tasks than just copying files.