Re: consdeev, com0 and remote management of servers

[kab00m <kab00m%lich.phys.spbu.ru@localhost>]

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:

1. Grub&linux have dual-console logic, BSD do not. So you will not be
able to manage BSD on screen, but sometimes switch to serial. However
there is no problem managing BSD through serial in permanent way,
both for console and boot-manager if you find needed options once.
Also using iDRAC, iRMC, ILOM and other service processors you always
can use graphic console (usually with Java-based client), which also 
always work.

2. Can you tell us why installboot way do not work for you?

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.

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.

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