port-i386/51898: NetBSD-7.0.2-i386-live-sd0root.img does not start up, and it can not mount by vndconfig.

[ryo_kato%webzoit.net@localhost]

>Number:         51898
>Category:       port-i386
>Synopsis:       NetBSD-7.0.2-i386-live-sd0root.img does not start up, and it can not mount by vndconfig.
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    port-i386-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Jan 19 03:50:00 +0000 2017
>Originator:     ryo
>Release:        7.0.2
>Organization:
private
>Environment:
NetBSD hp_netbsd.hp_netbsd.org 7.0.2 NetBSD 7.0.2 (GENERIC.201610210724Z) i386

>Description:
Since it has not been tried recently, it is unknown whether or not it has been corrected, but seem as it was not found in the Problem Report, we will report it.

The following Live Image for usb memstick does not start up, and it can not mount by vndconfig.

*NetBSD-7.0.2-i386-live-sd0root.img
(Building 11/27/2016)
*NetBSD-7.0.1_PATCH-i386-live-sd0root.img
(same build date above, maybe.)

It show error message of "mount_ffs: /dev/vnd0a on /mnt/img: incorrect super block" when mount it.

Sorry, I forgot concrete error message what had shown when boot from usb memstick...(That's might have shown whether "no slice" or  "no filesystem"...etc.) 

On the other hand, the image for HDD below can be mounted, and can also be started from QEMU.

*NetBSD-7.0.2-i386-live-wd0root.img
(Building 11/27/2016)
*NetBSD-7.0.1_PATCH-i386-live-wd0root.img
(same build date above, maybe.)

Depending on the timing of 7.0.1 build, sometimes it can not be mounted or booted too, but now I am using NetBSD-7.0.1-i386-live-sd0root.img with usb memstick.

>How-To-Repeat:
$ cd /any/path/usr/src
$ ./build.sh -U -O ../obj release live-image
$ cd ../release/images/
$ su -
Password:
# gzip -dc NetBSD-7.0.2-i386-live-sd0root.img.gz > any_path/sd0.img
# exit

$ sudo vndconfig -c vnd0 any_path/sd0.img
$ mount /dev/vnd0a /mnt/img
mount_ffs: /dev/vnd0a on /mnt/img: incorrect super block

$ sudo vndconfig -u vnd0


$ sudo dd if=any_path/wd0.img of=/dev/sd0f bs=1m
$ sudo reboot
...

(Select USB)

error
unable to boot from usb memstick...
>Fix: