Cannot install using serial console

[Jeremy Chadwick]

On Fri, Sep 10, 2010 at 08:38:30AM -0700, Jeremy Chadwick wrote:
> On Fri, Sep 10, 2010 at 05:18:00PM +0200, Jeremie Le Hen wrote:
> > On Fri, Sep 10, 2010 at 04:27:26AM -0700, Jeremy Chadwick wrote:
> > > > > As far as I know you need also to enable a serial terminal in /etc/ttys.
> > > > 
> > > > Yeah, this came to my mind too but I check on the installation CD, there
> > > > is no /etc/ttys.
> > > 
> > > This is normal.
> > > 
> > > Can you try hacking up a solution for yourself based on what I've
> > > documented with regards to PXE booting?  There will be pieces which
> > > obviously don't apply to you because you're booting from physical media,
> > > but some of the adjustments (to the bootloader, etc.) you can try.
> > > 
> > > http://jdc.parodius.com/freebsd/pxeboot_serial_install_8.html
> > 
> > But as far as I understand the handbook, this is not required to perform
> > the installation through sysinstall(8) on a serial console.  Modifying
> > /boot/loader.conf on the installation media is enough according to
> > chapter 2.12.1.  Am I wrong?
> 
> Nah you're not wrong -- I'm just not sure what the VM might be doing
> with/to the serial port.  I don't know what KVM you're using on Linux,
> but does the VM machine have a BIOS?  If so, does it offer something
> like serial console redirect capability?  If so, and it's enabled, it
> could/might be conflicting with the OS.
> 
> The reason I mention this: on some x86 systems that offer BIOS-level
> console redirection capability, the kernel (confirmed on both FreeBSD
> and Linux) can, depending on circumstances I'm not sure of, lock up the
> OS hard.
> 
> If the VM offers such a feature and you're not using it, try it (and
> remove the comconsole stuff from your loader.conf).  You might end up
> with VGA-over-serial that way, and it might suffice.
> 
> I imagine some form of getty(8) must be in use under the FreeBSD
> installation environment, because you can switch virtual consoles via
> Alt-<F1/F2...> as I'm sure you know.
> 
> > > One thing worth pointing out is that you stated the system that you're
> > > trying to use serial console on is actually running under a VM on Linux:
> > > 
> > > > I tried to install FreeBSD (201008 -CURRENT snapshot, but I don't think
> > > > it's important here) in a KVM-backed virtual machine on a headless Linux
> > > > host, following section 2.12.1 of the handbook.
> > > 
> > > Can you provide a full dmesg prior to the "/stand/sysinstal" output
> > > happening?  You don't need to boot verbose (yet), but it would help with
> > > regards to determining what the kernel is seeing device-wise.  Yes it
> > > matters.
> > 
> > Yes, I've actually already posted it in my original message:
> > http://lists.freebsd.org/pipermail/freebsd-stable/2010-September/058703.html
> 
> Thanks much -- for some reason that part of the Email is missing for me.
> 
> uart0: <Non-standard ns8250 class UART with FIFOs> port 0x3f8-0x3ff irq 4 flags 0x10 on acpi0
> uart0: [FILTER]
> uart0: console (9600,n,8,1)
> 
> It sure looks like it's console, but I'm not sure if there are
> implications/bugs that might stop serial I/O from working past a certain
> point for this type of chip, especially when under a VM.
> 
> Only other things I can think of trying, one at a time:
> 
> - Explicitly set a serial port speed using comconsole_speed in
>   loader.conf
> - Adding boot_serial="yes" to loader.conf
> - Try booting with ACPI disabled.  I'm not sure this will work under a
>   VM, but worth a shot I guess

Some other things that occurred to me:

1) Is the kernel built with SMP support?  I imagine that the stock
"out-of-the-box" images have SMP in use.  I don't know what happens on
FreeBSD if "options SMP" is present on a system which appears to lack
SMP (your dmesg output indicates only one CPU).

2) Does this problem happen with RELENG_8 (e.g. 8.1-RELEASE or an
8.1-STABLE snapshot)?

3) Can you try booting a livefs CD image (with loader.conf adjusted to
contain console="comconsole") and see if the behaviour is the same?  I'm
trying to figure out if it's something sysinstall somehow induces (I
imagine there's a little delay between the console output and when the
sysinstall binary has actually started), or if the kernel is doing
something.

-- 
| Jeremy Chadwick                                   jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |