inittab corrupted/serial console broken on Xen-ified kernel?

[Evan Lavelle]

[this is a message that I sent to xen-users yesterday, but I guess this 
list may be better - this looks like a problem either in Xen, or in the 
packaging of 2.6.21-2952.fc8xen].

I've just installed Fedora 8 / xen-2.6.21 on a headless server, but I
can't get a serial console login on the Xen version of the kernel.

1 - If I boot into 2.6.23.8-63.fc8, the serial console login works as
expected

2 - If I boot into 2.6.21-2952.fc8xen instead, I get all the expected
serial output up to the end of the boot process, but no login.

When I boot into the xen kernel, inittab is modified, and the
modification removes the agetty on ttyS0. If I compare the old inittab
with the new inittab, I get:

46,47c46
< # co:2345:respawn:/sbin/agetty xvc0 96 9600 vt100-nav
< co:12345:respawn:/sbin/agetty ttyS0 115200 vt100
---
>   co:2345:respawn:/sbin/agetty xvc0 96 9600 vt100-nav 
In other words, a commented entry was uncommented, and the following
line was deleted, which explains why I can't log in. This is so bizarre
that it almost looks like it was done on purpose (was it ? :))

Anyone seen this? Any ideas?

Thanks -

Evan

[Bill Nottingham]

Evan Lavelle (sa212+fcxen(a)cyconix.com) said: 
>  2 - If I boot into 2.6.21-2952.fc8xen instead, I get all the
> expected
>  serial output up to the end of the boot process, but no login.
>
>  When I boot into the xen kernel, inittab is modified, and the
>  modification removes the agetty on ttyS0. If I compare the old inittab
>  with the new inittab, I get:
>
>  46,47c46
>  < # co:2345:respawn:/sbin/agetty xvc0 96 9600 vt100-nav
>  < co:12345:respawn:/sbin/agetty ttyS0 115200 vt100
>  ---
>  >  co:2345:respawn:/sbin/agetty xvc0 96 9600 vt100-nav
>
>  In other words, a commented entry was uncommented, and the following
>  line was deleted, which explains why I can't log in. This is so bizarre
>  that it almost looks like it was done on purpose (was it ? :))
>
>  Anyone seen this? Any ideas? 
Xen takes over the serial port; it's modifying the line to point
to the xen console device.

Bill

[Evan Lavelle]

Bill Nottingham wrote:

> > 46,47c46
> > < # co:2345:respawn:/sbin/agetty xvc0 96 9600 vt100-nav
> > < co:12345:respawn:/sbin/agetty ttyS0 115200 vt100
> > ---
> >>  co:2345:respawn:/sbin/agetty xvc0 96 9600 vt100-nav
> > In other words, a commented entry was uncommented, and the following
> > line was deleted, which explains why I can't log in. This is so bizarre
> > that it almost looks like it was done on purpose (was it ? :))
> >
> > Anyone seen this? Any ideas?
>  
>  Xen takes over the serial port; it's modifying the line to point
>  to the xen console device. 
Interesting. So the "Serial Console Login configuration" in the manual 
(v3.0 User's Manual, p13) is wrong? The modified inittab is also 
incorrect; an error message appears on the serial output, and in the 
system logs, every 5 minutes ("Dec 14 17:52:35 thor init: Id "co" 
respawning too fast: disabled for 5 minutes").

How do I get a remote login over a serial line? Is this still possible?

Thanks -

Evan

[Bill Nottingham]

Evan Lavelle (sa212+fcxen(a)cyconix.com) said: 
> > Xen takes over the serial port; it's modifying the line to
> point
> > to the xen console device.
>
>  Interesting. So the "Serial Console Login configuration" in the manual 
>  (v3.0 User's Manual, p13) is wrong? The modified inittab is also incorrect; 
>  an error message appears on the serial output, and in the system logs, 
>  every 5 minutes ("Dec 14 17:52:35 thor init: Id "co" respawning too fast:
>
>  disabled for 5 minutes"). 
Yeah, the extra '96' seems wrong. Can you file a bug against kudzu?

>  How do I get a remote login over a serial line? Is this still
> possible? 
How are you booting xen? What's the command line?

Bill