Re: consdeev, com0 and remote management of servers

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

Hi Dima,

First of all, let me say how helpful I have found your input on this.
oComments interspersed below:

You wrote:
> 
> Hello, Steve,
> 
> As a person which have lot of serial consoles (NetBSD, FreeBSD, Solaris,
> Linux) working on very different platforms (Sun, IBM, HP) I can add
> something:
.
.
> 
> 2. Can you tell us why installboot way do not work for you?
 
I wish I could.   What I have found is that it is necessary to drop
out of the install system after partitioning and do an installboot -f
on /dev/wd0a to get the system to boot at all.  I have not been able
to discover why using " - o console=com0 " fails to work, nor why
"consdev=com0" in boot.cfg does not work whereas adding "consdev com0"
to tje command section of individual boot.cfg menu items does.  I have
wondered if the man page is out of step with the state of the software
in a way that those very familiar with the process would not
necessarily notice.
> 
> 3. 115200 vs 9600 is really helps, mostly when you manage file systems
> and lot of kernel output. I never set speed less than 115200.

Some of the Fujitsu on-screen prompts say it must be 38400. Not so.

> 
> 4. All this process is frustrating only first times when you are 
> understanding all the logic in this piece of software. After some
> experience you will do anything as a piece of cake.
> 

The NetBSD documentation in general is sane.   I'm not sure the same
can be said for the Fujitsu documentation.  In part it share what I
(as a former academic) think of as American textbookitis.  Roughly the
philosophy is not "here is a succinct exposition with some helpful
examples and exercises" but "in this chapter you will learn how to do
X,Y and Z: you probably don't want to do any of these, but tough,
that's what you're getting".  It suggests that the authors don't have
a real command of their material but only know some concrete
operations.

Also the BIOS on these machines behave oddly: you can have a device
that shows up in the list of SATA devices, but in the boot menu is on
a different port; the BIOS boot menu works only sporadically; it can
take several power cycles and quiescent periods for these things to
correct themselves.

I had more words with Fujitsu tech support this morning and they
suggest that there may be an issue concerning the boot filter
(UEFI/Legacy) which I shall pursue - although so far as I am aware I
have done everything in Legacy mode.

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

> On Fri, Apr 27, 2018 at 05:31:28PM +0000, Steve Blinkhorn wrote:
> > 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>
> 
> -- 
> Sincerely yours,
> Dima Veselov
> Physics R&D Establishment of Saint-Petersburg University
>