booting development image from USB gets "root mount failed"

nacho Lariguet lariguet at
Sun Aug 2 15:53:10 PDT 2020

On Thu, 30 Jul 2020 17:07:50 -0500
Jonathan Douglas Engwall <engwalljonathanthereal at> wrote:

> I have seen root mount failed but never with a risk that worked in another machine, if I follow.
> Maybe you should just try burning a new copy.
> Good luck :)

Thanks for your reply Jonathan.

This got me thinking, so from elsewhere on linux, I did the following:

dd if=/dev/zero of=/dev/sdx bs=4M conv=fsdatasync status=progress;

bzip2 --decompress --stdout ./DragonFly-x86_64-20200730-DEV-v5.9.0.653.gf9d29.boot.tar.bz2 \
   | dd of=/dev/sdx bs=4M conv=fsdatasync status=progress;

I tested this liveCD on another machine and so far so good.

Attempting to boot the Lenovo ThinkCentre M715q with this image
gets to the same mountroot> prompt. Typing ? produces:

"md0" "md0s0" "vn0" "vn1" "vn2" "vn3"

However, after a minute or so doing nothing else, just waiting,
the system starts showing messages related to da8; ie: being detected.
I don't remember seeing these messages before. Retyping ? shows:

"md0" "md0s0" "vn0" "vn1" "vn2" "vn3" "da8" "da8s1" "da8s2" ... and the like

Typing ufs:da8s2a and hitting enter continues the booting process as if
nothing unusual happened.

I don't know whether the problem regarding the USB key (delayed) detection
is due to buggy firmware code and/or lack of specific driver support for
this particular machine with dFly, but, the fact is that it is no more
than a minor annoyance to me at this time since it happens when installing
dFly and not every time I boot a freshly installed copy on a proper drive.

I tend to think buggy IBM/Lenovo firmware; but that's my two cents.

By the way; I successfully booted many linux liveCDs without a problem on
this machine in the past days, I even booted pfSense/freeBSD 11.3 and the

I will attempt to boot this same dFly liveCD on my PowerEdge server in these
days and keep you posted. Meanwhile I'll try to get a fully-functional dFly
installation on this Lenovo desktop PC to play with in order to plan my
server installation which is what I really want to begin with.

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