consdeev, com0 and remote management of servers

[steve%prd.co.uk@localhost (Steve Blinkhorn)]

After various helpful discussions off-list, I have come to a point where
there remains an issue concerning how to set the redirection of the
console over a remote management console.

It boils down to where and how to set consdev to com0, and how to
ensure that a remote session behaves nicely through the boot process
and into a multi-user login seamlessly.   There are three stagers to
this:

1. how to ensure that one can choose from the initial boot menu - it's
not much use if you can see the boot menu but not choose from it.

2. how to be sure that the hardware probe and rc.conf output can be
viewed remotely in real time.

3. how to end up with a usable login session via the remote management
console.

I have found that setting consdev=com0 in boot.cfg defeats choice from
the boot menu as does `installboot -e -v -o console=com0 ...` .  What
is more, no output from the hardware probe and rc.conf is visible
remotely.  Since my prime objective is to be able to fsck in
single-user mode, this was bad news.

However, dropping to the boot prompt and setting consdev to com0 does
allow you to boot and see all the initial diagnostics (and get to a
single-user shell).   Adding the following line in boot.cfg has the
same effect:

menu=Boot single user:rndseed /etc/entropy-file;consdev com0; boot netbsd -s 

The fact that consdev=com0 in boot.cfg does not have the same effect
does not align with the man page for boot.cfg(5).

Additionally, an entry in /etc/ttys for /dev/tty00 is needed to give a
clean multi-user terminal connection through the remote console.  I
have set all relevant line speeds to 115200 baud, and found no benefit
is using 9600 baud at any point.

I don't know how much of this is peculiar to the Fujitsu Primergy 1330
M3 R8 servers I am working on, but it's been a long and frustrating
journey, alleviated only by the customary kindly helpfulness of the NetBSD
community.

-- 
Steve Blinkhorn <steve%prd.co.uk@localhost>