[svlug] Booting to different kernel?

[Karen Shaeffer]

On Sun, Jun 08, 2014 at 07:25:30PM -0700, Scott DuBois wrote:
> On 06/07/2014 01:09 PM, Karen Shaeffer wrote:
> > On Sat, Jun 07, 2014 at 12:00:07AM -0700, crquan wrote:
> >>
> >> Yes, you may look /boot/grub/menu.lst and better to change in
> >> /etc/default/grub (For Ubuntu),
> >> there you may just change one line GRUB_DEFAULT=... and run
> >> update-grub to update
> >> /boot/grub/menu.lst; if you manually change /boot/grub/menu.lst,
> >> that's not recommended,
> >> because in future if you update ubuntu, get another kernel will
> >> overwrite /boot/grub/menu.lst,
> >> so you'd better to change /etc/default/grub, future kernel upgrades
> >> would take care of that,
> >>
> > --- end quoted text ---
> > 
> > Hi,
> > Yes, but that's the difference between someone who is an expert in linux
> > systems and a casual user. I would definitely prefer to manage my config
> > files myself. I've been doing that since 1997 and learn far more when some
> > script messes it up. On the other hand, my point of view isn't applicable
> > to most users and certainly wasn't best advice to John. In retrospect, I
> > should have just ignored the call for help and minded my own business.
> > 
> > enjoy,
> > Karen
> > 
> 
> Hmmm, don't know if this would be considered any kind of expert issue
> unless expert is anyone doing things beyond point-and-click users but,
> here are a couple of links that reference the material previously mentioned.
> 
Hi Scott,

I don't think grub requires too much expertise. It is very simplistic for
basic booting. You can get quite expert with network booting using pxe,
for example. I once helped Penguin Computing port Scyld clusterware from
RHEL4 to RHEL5, where I ported the compute nodes. And their use of pxe
was quite fun and interesting. The compute nodes were diskless. To run a
job, you needed to specify what software and resources were needed. And then
the nodes were booted using a double kernel process, and all the software
required to run the application was pulled in over the LAN as part of the
boot process. Using pxe in this environment, booting maybe hundreds or even
thousands of compute nodes required some expertise.

I manage my grub config files, because I have been known to run my own custom
kernels with custom commandline options configured in the grub config files, so
grub can pass them into the kernel at boot time. Running a stock Ubuntu or RedHat
kernel has its drawbacks, if you care about optimizing your operating system.

If you know what you are doing, managing your own grub config files doesn't
require much more effort than managing the grub user interface scripts, in
my opinion.

enjoy,
Karen
-- 
Karen Shaeffer                 Be aware: If you see an obstacle in your path,
Neuralscape Services           that obstacle is your path.        Zen proverb