CentOS - Jul 2015 - dual-booting <- Re: installing Cents os server 7.0

On Thu, Jul 2, 2015, 11:05 PM Warren Young <wyml at etr-usa.com> wrote:

>
> On Jul 2, 2015, at 9:21 PM, Chris Murphy <lists at colorremedies.com>
wrote:
> >
> > CentOS doesn't support dual boot, because I did all the work to
> > make that happen, the CentOS installer did nothing to help me make
> > this possible.
>
> If free space on a drive is available at time of installation, CentOS
will let you install itself into it, and it will even offer to put its boot
loader on a CentOS partition instead of overwriting the boot drive?s boot
sector.


The CentOS 7 installer does not support installing GRUB to a partition. It
can be installed, or not. If installed it goes in the MBR gap, or the
BIOSboot partition, or EFI System partition.

And because there's no ntfsprogs, grub2-mkconfig won't find Windows and
won't create a menu entry for it.
>
> That counts as ?supports dual boot? in my book.
 Supporting dual boot means ability to boot both installed OS's upon
completion of installing the second. This doesn't happen when the first OS
is Linux using LVM, or Windows, or OS X.

Merely installing into free space constituting dual boot support means
anything and everything supports dual boot to the point the term is
meaningless.

>
> I do not require that CentOS be able to *create* that free space.  That?s
my job.

 You have more jobs to do than that post-install to actually get it to dual
boot. The operative word is boot.

> Android only installs single-boot on hardware made specifically for it.
It can make up whatever rules it likes for that
hardware.
>
> You?re trying to extend that to CentOS pushing Windows aside on a machine
that came from the factory running Windows.  It?s a specious argument.

No I'm saying it does a better job doing what most of its users want it to
do rather than requiring them to knows esoteric things. It's not meant to
be an dual boot comparison.

And it's established that Cent OS does not push Windows aside. You have to
do that outside the CentOS installer.
>
> > Android managed to get where it is today has to do with what's
> > made all of these things more successful than Linux on the desktop and
> > that's simply better user experience.
>
> Until you explain how you?re going to get CentOS to be preinstalled on a
billion devices per year, I don?t see how you can connect Android?s success
to CentOS.  Where is the market force that will cause this to happen?

I'm not making a number of installs argument. I'm talking about user
experience.

For the significant minority who need dual boot, they are not at all well
served by these distros. Only Fedora really supports it, and only with
Windows, and only if Secure Boot isn't enabled.
> While I will agree that holding Option or C down on boot is worlds better
than madly pressing DEL and then poking around in a BIOS/EFI screen to
switch around the boot order, I don?t really see what this has to do with
the question at hand.  OS X?s installer won?t push a Windows installation
aside and make room for itself to dual-boot, either.

Correct. It does not support installing after Windows. Its dual boot
support is only supported when installing after Windows.

Of course it can be done with CLI tools by the user. But this isn't an
Apple supported configuration.
>
> You?re asking CentOS to *exceed* what Apple, Microsoft, and Google do
without giving it any of their market advantages first.

I'm asking that the CentOS installer not break bootability of the first
installed OS. And that to be "supporting dual boot" that two OS's
can in
fact be booted upon completion of the installation.

NTFS shrink is icing. It's not the main requirement.




>
> >> There is no shielded enclave where nothing changes, and nothing
breaks.
> >
> > Apple's installer. Nothing changes. Nothing's broken.
>
> Apple breaks stuff *all* *the* *time*.  They?re famous for it.
Not their installer. It's pretty much the same since ancient times. If
anything it now has fewer features.
>
> And I?m telling you this as an Apple fanboi.  I have accepted the fact
that I must cope with broken stuff on my Macs, just as I do on my CentOS
boxen.

OS X 10.n only on the computer. Then shrink that volume, and make a second
volume, and install 10.n+1. Both boot. Out of the box. No post install
work. Same for Windows.

RHEL/CentOS/Fedora? N and then N+1? N will fail to boot until you fix it
post install. And grub2-mkconfig won't help do it correctly in a way that
obviates having to always manually run it again.

Terrible UX.
>
> > Windows installer? Nothing changes. Nothing's broken.
>
> Go compare the standard paths for changing network settings in Windows
2000, XP, Vista, 7, 8, and 10, and tell me Microsoft never moves things
around.

Installer. You said there is no shielded enclave. All I had to do to prove
that wrong was provide one example. I provided two.

But at least you let the Secure Boot arguing go...

Chris Murphy

Wow. So many _passionate_ words. Still have no idea what Chris is really
going on about.

??This seems to be running in two threads in Gmail, which makes it even
more confusing.

K

On Jul 3, 2015, at 12:23 AM, Chris Murphy <lists at colorremedies.com>
wrote:
> 
> On Thu, Jul 2, 2015, 11:05 PM Warren Young <wyml at etr-usa.com>
wrote:
> 
>> Until you explain how you?re going to get CentOS to be preinstalled on
a
> billion devices per year, I don?t see how you can connect Android?s success
> to CentOS.  Where is the market force that will cause this to happen?
> 
> I'm not making a number of installs argument. I'm talking about
user
> experience.
It makes no sense to talk about the UX of CentOS as compared to Android while
ignoring the billions of dollars that flow into the Android ecosystem.  You
cannot expect CentOS UX to approach or exceed Android?s UX without giving it
equivalent resources.
> OS X 10.n only on the computer. Then shrink that volume, and make a second
> volume, and install 10.n+1. Both boot. Out of the box. No post install
> work. Same for Windows.
> 
> RHEL/CentOS/Fedora? N and then N+1? N will fail to boot until you fix it
> post install. And grub2-mkconfig won't help do it correctly in a way
that
> obviates having to always manually run it again.
> 
> Terrible UX.
Now you?re finally talking sense.

I agree, Linuxes generally should be able to push other Linux installs around,
dual-boot, etc.  I will even go so far as to say that it is not unreasonable to
expect that, say, Debian should be able to carve a slice for itself on a
computer currently monopolized by CentOS.

You?ll be working on fixing this as soon as you?re done writing emails about it,
right? :)
> But at least you let the Secure Boot arguing go?
You misunderstand.  I am not on a crusade, like you seem to be.  I can make my
point and move on.  I have no need to keep making the same point again and again
and again, all on the wrong list.

IMHO dual booting, although interesting, is a dying technology. A necessary
hack from less civilised times.

The modern approach is to choose the OS that personally gives you the most
comfort (legal, physical, moral, aesthetic, financial, ...) and use
virtualization to boot any other OS you may need.

Investing time in improving the UX for dual-booting may be fun or satisfy
the soul, but it seems inappropriate to suggest its an important issue that
must be resolved. Personally I'd choose investing my time in improving
virtualization.

K

Chris Murphy wrote:
>  Supporting dual boot means ability to boot both installed OS's upon
> completion of installing the second. This doesn't happen when the first
OS
> is Linux using LVM, or Windows, or OS X.
In that case, wouldn't it be more precise to say: CentOS-7 doesn't
support
dual boot if you are using LVM?
It seems to me to work reasonably well with ext4.
Does it work with LVM if you have a separate ext4 /boot partition?

-- 
Timothy Murphy  
gayleard /at/ eircom.net
School of Mathematics, Trinity College, Dublin

On 07/03/2015 02:51 AM, Kahlil Hodgson wrote:
> Wow. So many _passionate_ words. Still have no idea what Chris is really
> going on about.
Yeah, it's one of those threads with "more heat than light."

I believe that Chris wants (among many other things) is a CentOS which 
will automatically resize an existing Windows or OSX partition when 
setting up a dual-boot machine.  I suspect that it doesn't (and won't, 
and actually shouldn't) due to legal and PR reasons.  That is, if some 
user clicks on a button which says "Resize [other] partition", someone
somewhere sometime is going to complain that a Linux install messed up 
her Windows or OSX partition.  This could lead to a legal and/or PR 
nightmare for Linux and Linux devs.  For these reason I'd think it 
better that, if you want to manipulate, say, a Windows partition, we're 
all better off if you do that with Windows software or at least 
separately from a no-brain-required Linux install program.

Just to respond to one objection in advance (because I'm not going to be 
drawn into this thread anymore than I have), years ago, in the early 
days of dual-boot, Windows put a critical and non-moveable file at the 
end of their partition.  This made blithely shrinking that partition 
either impossible or dangerous-- so quite risky.  And to me and everyone 
I knew there seemed to be no reason at all for this file being where and 
how it was, except to make shrinking the partition difficult.  If you 
went into Windows, however, and knew the three or four steps, you could 
move this file and then, outside of Windows, resize the partition, then 
proceed with the dual-boot install.

Now imagine a Linux dual-boot install which automatically resized a 
Windows partition.  Then imagine a Windows software update which 
included some such Gatesenheimer in it.  The above-mentioned nightmare 
would begin and a lot of people would be called in for jury duty over 
something they didn't and wouldn't understand.  Settled out of court, 
there'd begin a fee on Linux to cover damages assessed by the 
settlement.  The Linux devs would probably have to go work for MS at 
minimum wage to cover or comply with their part of that settlement. 
Absurd and paranoid scenario?  Yes.  Possible?  Still yes.


Peace out.

On Fri, Jul 3, 2015 at 4:42 AM, Timothy Murphy <gayleard at eircom.net>
wrote:
> Chris Murphy wrote:
>
>>  Supporting dual boot means ability to boot both installed OS's
upon
>> completion of installing the second. This doesn't happen when the
first OS
>> is Linux using LVM, or Windows, or OS X.
>
> In that case, wouldn't it be more precise to say: CentOS-7 doesn't
support
> dual boot if you are using LVM?
Or using Windows or OS X (just an ugly failure in that it causes XNU
to panic, but it hasn't actually injured anything, it is still
possible to boot OS X via the firmware boot manager).
> It seems to me to work reasonably well with ext4.
Correct. If the existing OS uses ext3/4 on standard partitions, then
the installer can do fs shrink, and when it calls grub2-mkconfig, the
installation is found and boot entries are created for it. That the
boot entry is distinctly sub-optimal is a long standing GRUB problem
not an installer problem and not a CentOS problem per se. But it's
still sloppy. The tools already exist for this to be done better, but
for reasons unknown GRUB upstream likes to do things the hard and sub
optimal way whenever possible.
> Does it work with LVM if you have a separate ext4 /boot partition?
No. The root fs is hidden in an inactive LV, so os-prober (via
grub2-mkconfig) won't find that Linux installation. The installer
should make all LVs active so os-prober can find other OS's and make
boot entries for them, but it doesn't.


-- 
Chris Murphy