CentOS virt - May 2017 - What is the purpose setting console=hvc0 in the dom0 grub config?

On Wed, May 17, 2017 at 8:44 AM, George Dunlap <dunlapg at umich.edu>
wrote:
> On Wed, May 17, 2017 at 4:20 PM, Jerry <jerryubi at gmail.com> wrote:
> > This is what's defined in /etc/default/grub following the install
of the
> > Xen:
> >
> > GRUB_CMDLINE_XEN_DEFAULT="dom0_mem=1024M,max:1024M cpuinfo
> com1=115200,8n1
> > console=com1,tty loglvl=all guest_loglvl=all"
> > GRUB_CMDLINE_LINUX_XEN_REPLACE_DEFAULT="console=hvc0
earlyprintk=xen
> > nomodeset"
> >
> > I didn't set these myself, this is what the xen package (or one of
its
> > dependencies) is doing.
>
> It's the CentOS Xen package setting this.  But the Xen option
> "console=com1,tty" should make it such that Xen sends its output
> *both* to the serial line, *and* the monitor.
>
> I take it you're not seeing any Xen output at all on your IPMI console?
>
>  -George
>
The boot messages are suppressed, but if it boots successfully the login
prompt shows up. If I remove console=hvc0 both the boot messages and login
prompt show up.

Note: the IPMI console I'm looking at is just the local monitor being
redirected.  It isn't a special device/driver.

I'll try what Konrad is suggesting, setting this:

console=hvc0 console=tty

And will see what happens.  It'll be a few hours until I can try it out.

Thank you to every one that has responded, I appreciate the help.

Jerry.
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On Wed, May 17, 2017 at 8:54 AM, Jerry <jerryubi at gmail.com> wrote:
>
>
> On Wed, May 17, 2017 at 8:44 AM, George Dunlap <dunlapg at umich.edu>
wrote:
>
>> On Wed, May 17, 2017 at 4:20 PM, Jerry <jerryubi at gmail.com>
wrote:
>> > This is what's defined in /etc/default/grub following the
install of the
>> > Xen:
>> >
>> > GRUB_CMDLINE_XEN_DEFAULT="dom0_mem=1024M,max:1024M cpuinfo
>> com1=115200,8n1
>> > console=com1,tty loglvl=all guest_loglvl=all"
>> > GRUB_CMDLINE_LINUX_XEN_REPLACE_DEFAULT="console=hvc0
earlyprintk=xen
>> > nomodeset"
>> >
>> > I didn't set these myself, this is what the xen package (or
one of its
>> > dependencies) is doing.
>>
>> It's the CentOS Xen package setting this.  But the Xen option
>> "console=com1,tty" should make it such that Xen sends its
output
>> *both* to the serial line, *and* the monitor.
>>
>> I take it you're not seeing any Xen output at all on your IPMI
console?
>>
>>  -George
>>
>
> The boot messages are suppressed, but if it boots successfully the login
> prompt shows up. If I remove console=hvc0 both the boot messages and login
> prompt show up.
>
> Note: the IPMI console I'm looking at is just the local monitor being
> redirected.  It isn't a special device/driver.
>
> I'll try what Konrad is suggesting, setting this:
>
> console=hvc0 console=tty
>
> And will see what happens.  It'll be a few hours until I can try it
out.
>
> Thank you to every one that has responded, I appreciate the help.
>
> Jerry.
>
>
Setting both hvc0 and tty is working as desired.  Thanks again to everyone
that replied.  I'm updating my kickstart script to include adding
console=tty in addition to the other.

Jerry
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On Wed, 17 May 2017 14:09:57 -0700 Jerry <jerryubi at gmail.com> wrote:
> Setting both hvc0 and tty is working as desired.  Thanks again to everyone
> that replied.  I'm updating my kickstart script to include adding
> console=tty in addition to the other.
Should it be set by default then?

Regards,
Nerijus