CentOS docs - Jun 2015 - wiki.centos.org/TipsAndTricks/VncHeadlessInstall

(Apologies for the potential duplicate post.  My initial post had a 
smashed subject line.  This post only adds the subject and this note.)

I would like permission to edit this page.  The changes I have in mind are:

1) It is not necessary to burn a CD/DVD to do a "headless" install in 
cases where the installed system has a monitor, but for some reason 
cannot support a graphical install directly.   This can be caused by: a 
server that has too little memory to run a graphical install, or running 
the install in a virtual machine where the install does not work 
properly in the virtual machine console because the display is too small 
and controls are not shown.

One situation where I ran into this situation was doing an install of 
6.5 on very old server hardware.  The text mode install did not allow me 
to preserve partitions, and it was critical to preserve the /home mount 
to avoid data loss.  I had to run the graphical install, but the only 
way to do it on this hardware was to do a headless install.  I was 
thankful for the page because it helped me figure out how to do the 
headless install even though I didn't need to go to the trouble of 
making bootable media.  It seems potentially beneficial to make notes 
that help others also learn how to do it without burning media if this 
could solve their issue.

Also, just last week I tried to perform a graphical install CentOS 7.1 
in a VM under ESXi 6.  The install started out okay, but soon reached a 
point where installer windows/panels and controls did not fit in the 
console display.  While one might try to use TAB to select hidden 
controls, it was unsafe to do so because one could not even see the 
controls that needed to be manipulated.  As I didn't know how to cure 
the console size issue during install, it seemed logical to use a 
"headless" install method to get a higher resolution install console
via
a VNC viewer.  This might have worked except that:

2) The instructions given do not work for CentOS 7.  Something has 
changed.  At this point I am still trying to figure out if the problem 
is simply a matter of changed kernel options, but after trying many 
things for a couple of days, it is clear that at least 7.1 does not 
work.  At the very least, the page could be improved by documenting this 
difficulty with 7.  I did find a lead tonight that might allow me to 
proceed with 7, but I haven't tested it yet.  If it works, then the 
edits would document changes key to making the process work for 7.

The proposed edits would show how to invoke a "headless" install by 
editing kernel parameters at the initial install menu on the console.  
Obviously this is not a true "headless install", but since it can be 
used to advantage, and as it is A LOT simpler than burning a CD/DVD, I 
feel the changes would help others that find themselves in the situation 
I was in.

I am proposing to do the in 
http://wiki.centos.org/TipsAndTricks/VncHeadlessInstall though if it is 
felt that it is better to have the content be on a sub-page (due to the 
fact my edits involve using the console), I am amenable to doing that also.

My wikiuser is:   KevinBulgrien

I have not created my user page at this time, but would plan to follow 
the editing guidelines and set it up if I am approved to make these 
changes.

Thanks for your consideration of this matter.

Kevin Bulgrien




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On 30 June 2015 at 05:46, Kevin Bulgrien <kbulgrien at att.net>
wrote:
>
> (Apologies for the potential duplicate post.  My initial post had a smashed
subject line.  This post only adds the subject and this note.)
>
> I would like permission to edit this page.  The changes I have in mind are:
>
> 1) It is not necessary to burn a CD/DVD to do a "headless"
install in cases where the installed system has a monitor, but for some reason
cannot support a graphical install directly.   This can be caused by: a server
that has too little memory to run a graphical install, or running the install in
a virtual machine where the install does not work properly in the virtual
machine console because the display is too small and controls are not shown.
>
> One situation where I ran into this situation was doing an install of 6.5
on very old server hardware.  The text mode install did not allow me to preserve
partitions, and it was critical to preserve the /home mount to avoid data loss. 
I had to run the graphical install, but the only way to do it on this hardware
was to do a headless install.  I was thankful for the page because it helped me
figure out how to do the headless install even though I didn't need to go to
the trouble of making bootable media.  It seems potentially beneficial to make
notes that help others also learn how to do it without burning media if this
could solve their issue.
>
> Also, just last week I tried to perform a graphical install CentOS 7.1 in a
VM under ESXi 6.  The install started out okay, but soon reached a point where
installer windows/panels and controls did not fit in the console display.  While
one might try to use TAB to select hidden controls, it was unsafe to do so
because one could not even see the controls that needed to be manipulated.  As I
didn't know how to cure the console size issue during install, it seemed
logical to use a "headless" install method to get a higher resolution
install console via a VNC viewer.  This might have worked except that:
>
> 2) The instructions given do not work for CentOS 7.  Something has changed.
At this point I am still trying to figure out if the problem is simply a matter
of changed kernel options, but after trying many things for a couple of days, it
is clear that at least 7.1 does not work.  At the very least, the page could be
improved by documenting this difficulty with 7.  I did find a lead tonight that
might allow me to proceed with 7, but I haven't tested it yet.  If it works,
then the edits would document changes key to making the process work for 7.
>
> The proposed edits would show how to invoke a "headless" install
by editing kernel parameters at the initial install menu on the console. 
Obviously this is not a true "headless install", but since it can be
used to advantage, and as it is A LOT simpler than burning a CD/DVD, I feel the
changes would help others that find themselves in the situation I was in.
>
> I am proposing to do the in
http://wiki.centos.org/TipsAndTricks/VncHeadlessInstall though if it is felt
that it is better to have the content be on a sub-page (due to the fact my edits
involve using the console), I am amenable to doing that also.
>
> My wikiuser is:   KevinBulgrien
>
> I have not created my user page at this time, but would plan to follow the
editing guidelines and set it up if I am approved to make these changes.
>
> Thanks for your consideration of this matter.
>
> Kevin Bulgrien
Hello Kevin,

I have created a wiki home page for you
(wiki.centos.org/KevinBulgrien) and would suggest that you use it to
lay out your proposed changes in a draft form. When done, just ask on
this list for a review and comments and then your contribution(s) can
be merged.

I have appended a copy of the /TipsAndTricks/VncHeadlessInstall page
to your home page so that you have something to work with.

Alan.