upgrading a system to NetBSD 10 using sysinst vs sysupgrade

[Ramiro Aceves <ea1abz%gmail.com@localhost>]

Hello,

I have some doubts about the NetBSD upgrading procedure, now that we are 
closer to NetBSD release I want to do things right.

I installed NetBSD 9.3 in my Intel Nuc 8i7 but I had some problems to 
get Xorg Modesetting driver working so I  decided to upgrade the system 
to NetBSD-Current using sysutils/sysupgrade program. Everything went ok 
in Xorg as I told in this mailing list.

Days after, I was trying to compile some programs and decided to install 
the Xorg source set. I run #sysinst program from the running system to 
install several sets. Also by mistake I installed kernel, base (I 
believed that they will be uninstalled if not marked selected on the 
screen). But I also installed the /etc  set over my /etc files and 
everything screwed up :-) I believed that the /etc set would mix 
carefully with the existing files as sysupgrade did but it simply copied 
over them, deleting configuration files. Of course /etc/rc.conf was 
destroyed. :-)

After reading the chapter "rescuing a system" could fix it. Great!

http://www.netbsd.org/docs/misc/index.html#why-single-user

It was a good learning experience, indeed. Now uname says I am at NetBSD 
10.0_RC1.


Reading the NetBSD Guide I see that upgrades can be done using sysinst 
(a bit more confortable than sysupgrade) but says that:

"  To do the upgrade, you must have some form of bootable media (CD-ROM, 
USB drive, floppy, etc.) available and at least the base and kern 
distribution sets. "

My doubt is: can sysint be executed from the running system and upgraded 
from the internet using the configured system network? Or upgrade must 
be run from the bootable media?

Thanks in advance.

Ramiro.