f9 grub kernel arguments and kickstart questions

[Skunk Worx]

Hi,

I see that my f9 installs have a grub kernel argument 'root=UUID={hex}'

Could someone tell me a little about this? I've used things like 
root=/dev/VolGroup00/LogVol00 for seems like ages.

Does this impact things like disk cloning or jumbling packs between 
machines?

If so, is there a way to specify the older method in a kickstart file?

Also I know I can 'append' things in kickstart like "vga=791 acpi=force 
reboot=b', but can I remove the 'rhgb quiet'?

Thanks,
John

[Skunk Worx]

Tim wrote:
>  On Fri, 2008-06-13 at 21:54 -0700, Skunk Worx wrote:
> > I see that my f9 installs have a grub kernel argument
> > 'root=UUID={hex}'
> >
> > Could someone tell me a little about this? I've used things like 
> > root=/dev/VolGroup00/LogVol00 for seems like ages.
>  
>  It's a unique ID for each partition.  The system can tell one partition
>  apart from another, no matter what the volume label, or physical
>  location (e.g. /dev/hda).  Meaning that you can always refer to a
>  partition by it's UUID, and get the right one, no matter where it's
>  connected.
>  
> > Does this impact things like disk cloning or jumbling packs between 
> > machines?
>  
>  Yes.  Depending on your needs, it makes life easier, or more difficult.
>  
>  If you want to move a drive about, and not have it clash with other
>  drives using the same volume labels (e.g. having fights with two drives
>  both labelled as /home or both as LogVol00), then UUID is a great
>  benefit.
>  
>  On the other hand, if you want to take /home from one box and re-use it
>  as /home in another box, you'll need to rewrite the fstab file to either
>  use labels, or change the UUID from the old to the new.
>  
>  I can't see it being a problem if you're cloning a drive.  An exact copy
>  of one drive should be an exact copy.  So a clone should work as a drop
>  in replacement.
>  
>  Though if you're cloning drives to turn a group of drives into an array,
>  something tells me that that's going about things in the wrong way.
>   
I won't have the issue of two root drives installed in the same machine, 
and I won't be moving /home between machines.

I will definitely have the issue of installation on one machine and 
runtime on another, and the issue of N packs installed in N machines in 
some random order.

I doubt I'll have any array cloning other than the obvious...we might 
have a tower with a master drive cloned to several target drives 
simultaneously. But it will be N disks into N machines at runtime.

Sounds like I'll be fine in any case. My concern was the UUID could 
somehow be constructed from the mac address or other things, linking the 
drive to the machine, like you-know-who tends to do.

> > If so, is there a way to specify the older method in a kickstart
> file?
>  
>  You can refer to them just the same as you did beforehand (device names,
>  volume labels, or volume groups).
>   
I've always used the basic anaconda generated config from 
post-dvd-install and modified that. The anaconda/kickstart 
documentation, and the comments in the kickstart file, do not make it 
clear (at least not to me!) how to specify a root=/VolGroup00/LogVol00 
vs. a root=UUID= definition.

It's no problem to edit this after the install, just a curiosity.

Does anyone have a syntax example of how to differentiate these in a ks 
file?

> > Also I know I can 'append' things in kickstart like
> "vga=791
> > acpi=force reboot=b', but can I remove the 'rhgb quiet'?
>  
>  "rhgb" is an *optional* graphical boot progress display.  I found
>  booting quicker without the additional delay caused when this starts up.
>  And others have found they've had less graphic card driver problems
>  without it, too.
>  
>  "quiet" is an *option* to hide some of the messages printed when the
>  system starts to boot.
>   
Sorry my question was not clear...I want to *remove* the two options via 
kickstart...have them not be in the grub.conf after the network install.

I know I can append things, but these two options always seem to be 
there, forcing me to edit them out after the installation. It's no 
problem to do that, but if I can do it in kickstart it's one less change 
I have to make later.

I prefer  the older text scrolling...even if it takes a little longer to 
boot...our installs have to run on a lot of different cards and displays 
and IMHO this has been a more reliable way to see failure messages 
during the boot sequence.

Thanks,
John

[Skunk Worx]

Antonio Olivares wrote:
>  
>  
>  --- On Fri, 6/13/08, Skunk Worx <skunkworx(a)verizon.net&gt; wrote:
>  
> > From: Skunk Worx <skunkworx(a)verizon.net&gt;
> > Subject: f9 grub kernel arguments and kickstart questions
> > To: "For users of Fedora Core releases" <fedora-list(a)redhat.com&gt;
> > Date: Friday, June 13, 2008, 9:54 PM
> > Hi,
> >
> > I see that my f9 installs have a grub kernel argument
> > 'root=UUID={hex}'
> >
>  In my computer, only the default Fedora 9 kernel installs such an entry, the others
> appear to be normal
>   
Huh. I'll have to take a look at this.

I have releases/Everything and updates in my local repo, and I think I 
am getting the newest kernel on a ks install with the root=UUID line.

But I won't be able to verify this until Tuesday.

> >
> > Also I know I can 'append' things in kickstart like
> > "vga=791 acpi=force 
> > reboot=b', but can I remove the 'rhgb quiet'?
> >
>  Yes you may.  Booting still works fine :)
> > Thanks,
> > John
> > 
Yes...I wasn't clear enough. It seem the two options are there by 
default and I prefer them not to be :-) It's just preference and no 
problem to take them out after the install. But one less thing to do 
after the network install is preferred.

> > -- 
>  
>  Regards,
>  
>  Antonio 
>

[Tim]

Skunk Worx:
>  Sounds like I'll be fine in any case. My concern was the UUID
> could 
>  somehow be constructed from the mac address or other things, linking the 
>  drive to the machine, like you-know-who tends to do. 
As far as I'm aware, it's just pseudo-random content to generate a
hopefully unique ID.

>  Sorry my question was not clear...I want to *remove* the two options
> via 
>  kickstart...have them not be in the grub.conf after the network install. 
If you don't want RHGB, then you could try removing its RPM package from
the installation list.

>  I prefer  the older text scrolling...even if it takes a little longer
> to 
>  boot...our installs have to run on a lot of different cards and displays 
>  and IMHO this has been a more reliable way to see failure messages 
>  during the boot sequence. 
Me too, while I've found RHGB handy because it can show more text on
screen (when you open the details) and I can easily scroll back and see
something that's gone off the top of the screen, I've found it quicker
to boot without it.  Starting RHGB adds a significant delay (even on a
1.6 GHz CPU system), and there seems to be yet another one as it exits
and GDM starts up.

I haven't observed whether things are quicker, or not, with the quiet
option.  But the computer just sits there displaying no progress for a
few moments during the same time that text would have been whizzing
past.  I suspect the timing wouldn't be much different.

-- 
[tim@localhost ~]$ uname -r
2.6.25.6-55.fc9.i686

Don't send private replies to my address, the mailbox is ignored.  I
read messages from the public lists.

[Skunk Worx]

Craig White wrote:
>  On Sat, 2008-06-14 at 10:12 -0700, Skunk Worx wrote:
> > Antonio Olivares wrote:
> >>
> >> --- On Fri, 6/13/08, Skunk Worx <skunkworx(a)verizon.net&gt; wrote:
> >>
> >>> From: Skunk Worx <skunkworx(a)verizon.net&gt;
> >>> Subject: f9 grub kernel arguments and kickstart questions
> >>> To: "For users of Fedora Core releases"
> <fedora-list(a)redhat.com&gt;
> >>> Date: Friday, June 13, 2008, 9:54 PM
> >>> Hi,
> >>>
> >>> I see that my f9 installs have a grub kernel argument
> >>> 'root=UUID={hex}'
> >>>
> >> In my computer, only the default Fedora 9 kernel installs such an entry, the
> others appear to be normal
> >>
> > Huh. I'll have to take a look at this.
> >
> > I have releases/Everything and updates in my local repo, and I think I 
> > am getting the newest kernel on a ks install with the root=UUID line.
> >
> > But I won't be able to verify this until Tuesday.
> >
> >>> Also I know I can 'append' things in kickstart like
> >>> "vga=791 acpi=force 
> >>> reboot=b', but can I remove the 'rhgb quiet'?
> >>>
> >> Yes you may.  Booting still works fine :)
> >>> Thanks,
> >>> John
> >>>
> > Yes...I wasn't clear enough. It seem the two options are there by 
> > default and I prefer them not to be :-) It's just preference and no 
> > problem to take them out after the install. But one less thing to do 
> > after the network install is preferred.
>  ----
>  I haven't given it much thought but it surely would be possible to use a
>  post-installation script to do something like 
>  
>  sed -i 's/rhgb quiet//g' /boot/grub/grub.conf
>  
>  to remove them
>  
>  Craig
>   
I agree and I'll have to try this. However as I recall (dimly) there are 
some changes to the install that are finalized after the post-install 
section, which is why I prefer the up front, deterministic approach when 
I can get away with it!

---
John

[Craig White]

On Sat, 2008-06-14 at 10:12 -0700, Skunk Worx wrote:
>  Antonio Olivares wrote:
>  > 
>  > 
>  > --- On Fri, 6/13/08, Skunk Worx <skunkworx(a)verizon.net&gt; wrote:
>  > 
>  >> From: Skunk Worx <skunkworx(a)verizon.net&gt;
>  >> Subject: f9 grub kernel arguments and kickstart questions
>  >> To: "For users of Fedora Core releases"
> <fedora-list(a)redhat.com&gt;
>  >> Date: Friday, June 13, 2008, 9:54 PM
>  >> Hi,
>  >>
>  >> I see that my f9 installs have a grub kernel argument
>  >> 'root=UUID={hex}'
>  >>
>  > In my computer, only the default Fedora 9 kernel installs such an entry, the others
> appear to be normal
>  > 
>  
>  Huh. I'll have to take a look at this.
>  
>  I have releases/Everything and updates in my local repo, and I think I 
>  am getting the newest kernel on a ks install with the root=UUID line.
>  
>  But I won't be able to verify this until Tuesday.
>  
>  >>
>  >> Also I know I can 'append' things in kickstart like
>  >> "vga=791 acpi=force 
>  >> reboot=b', but can I remove the 'rhgb quiet'?
>  >>
>  > Yes you may.  Booting still works fine :)
>  >> Thanks,
>  >> John
>  >>
>  
>  Yes...I wasn't clear enough. It seem the two options are there by 
>  default and I prefer them not to be :-) It's just preference and no 
>  problem to take them out after the install. But one less thing to do 
>  after the network install is preferred. 
----
I haven't given it much thought but it surely would be possible to use a
post-installation script to do something like 

sed -i 's/rhgb quiet//g' /boot/grub/grub.conf

to remove them

Craig

[Tim]

On Fri, 2008-06-13 at 21:54 -0700, Skunk Worx wrote:
>  I see that my f9 installs have a grub kernel argument
>  'root=UUID={hex}'
>  
>  Could someone tell me a little about this? I've used things like 
>  root=/dev/VolGroup00/LogVol00 for seems like ages. 
It's a unique ID for each partition.  The system can tell one partition
apart from another, no matter what the volume label, or physical
location (e.g. /dev/hda).  Meaning that you can always refer to a
partition by it's UUID, and get the right one, no matter where it's
connected.

>  Does this impact things like disk cloning or jumbling packs between 
>  machines? 
Yes.  Depending on your needs, it makes life easier, or more difficult.

If you want to move a drive about, and not have it clash with other
drives using the same volume labels (e.g. having fights with two drives
both labelled as /home or both as LogVol00), then UUID is a great
benefit.

On the other hand, if you want to take /home from one box and re-use it
as /home in another box, you'll need to rewrite the fstab file to either
use labels, or change the UUID from the old to the new.

I can't see it being a problem if you're cloning a drive.  An exact copy
of one drive should be an exact copy.  So a clone should work as a drop
in replacement.

Though if you're cloning drives to turn a group of drives into an array,
something tells me that that's going about things in the wrong way.

>  If so, is there a way to specify the older method in a kickstart
> file? 
You can refer to them just the same as you did beforehand (device names,
volume labels, or volume groups).

>  Also I know I can 'append' things in kickstart like
> "vga=791
>  acpi=force reboot=b', but can I remove the 'rhgb quiet'? 
"rhgb" is an *optional* graphical boot progress display.  I found
booting quicker without the additional delay caused when this starts up.
And others have found they've had less graphic card driver problems
without it, too.

"quiet" is an *option* to hide some of the messages printed when the
system starts to boot.

-- 
[tim@localhost ~]$ uname -r
2.6.25.6-55.fc9.i686

Don't send private replies to my address, the mailbox is ignored.  I
read messages from the public lists.

[Antonio Olivares]

--- On Fri, 6/13/08, Skunk Worx <skunkworx(a)verizon.net&gt; wrote:

>  From: Skunk Worx <skunkworx(a)verizon.net&gt;
>  Subject: f9 grub kernel arguments and kickstart questions
>  To: "For users of Fedora Core releases" <fedora-list(a)redhat.com&gt;
>  Date: Friday, June 13, 2008, 9:54 PM
>  Hi,
>  
>  I see that my f9 installs have a grub kernel argument
>  'root=UUID={hex}'
>  
In my computer, only the default Fedora 9 kernel installs such an entry, the others
appear to be normal

# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /boot/, eg.
#          root (hd0,2)
#          kernel /vmlinuz-version ro root=/dev/VolGroup00/LogVol00
#          initrd /initrd-version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,2)/grub/splash.xpm.gz
hiddenmenu
title Fedora (2.6.25.6-55.fc9.x86_64)
	root (hd0,2)
	kernel /vmlinuz-2.6.25.6-55.fc9.x86_64 ro root=/dev/VolGroup00/LogVol00 rhgb quiet
	initrd /initrd-2.6.25.6-55.fc9.x86_64.img
title Fedora (2.6.25.4-30.fc9.x86_64)
	root (hd0,2)
	kernel /vmlinuz-2.6.25.4-30.fc9.x86_64 ro root=/dev/VolGroup00/LogVol00 rhgb quiet
	initrd /initrd-2.6.25.4-30.fc9.x86_64.img
title Fedora (2.6.25.3-18.fc9.x86_64)
	root (hd0,2)
	kernel /vmlinuz-2.6.25.3-18.fc9.x86_64 ro root=/dev/VolGroup00/LogVol00 rhgb quiet
	initrd /initrd-2.6.25.3-18.fc9.x86_64.img
title Fedora (2.6.25-14.fc9.x86_64)
	root (hd0,2)
	kernel /vmlinuz-2.6.25-14.fc9.x86_64 ro root=UUID=72f4731d-a8f3-4c89-a4da-98bc778e88f5
rhgb quiet
	initrd /initrd-2.6.25-14.fc9.x86_64.i

The rest I do not know, I only can respond as what I have seen here :)

Hopefully someone can tell you, if you need to worry or not?

>  
>  Could someone tell me a little about this? I've used
>  things like 
>  root=/dev/VolGroup00/LogVol00 for seems like ages.
>  
>  Does this impact things like disk cloning or jumbling packs
>  between 
>  machines?
>  
>  If so, is there a way to specify the older method in a
>  kickstart file?
>  
>  Also I know I can 'append' things in kickstart like
>  "vga=791 acpi=force 
>  reboot=b', but can I remove the 'rhgb quiet'?
>  
Yes you may.  Booting still works fine :)
>  
>  Thanks,
>  John
>  
>  --  
Regards,

Antonio