[gentoo-user] Kernel upgrade question: is it adviseable?

[gentoo-user] Kernel upgrade question: is it adviseable?

[James Homuth]

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I noticed yesterday gentoo-sources-2.6.29 was released, and was wondering if
it's required that the kernel be upgraded (I'm currently running 2.6.28. I
did download the sources (Should I have done that?), but in the event it's
not mandatory or anything to upgrade the kernel I'd really like to not have
to recompile the thing. Related, however, if I do recompile it and decide to
do so with genkernel, will it respect the settings I've compiled into 2.6.28
or will they need to be reset again before 2.6.29 is compiled? thanks for
any information on the subject.

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Re: [gentoo-user] Kernel upgrade question: is it adviseable?

[Alan McKinnon]

On Wednesday 03 June 2009 17:43:56 James Homuth wrote:
> I noticed yesterday gentoo-sources-2.6.29 was released, and was wondering
> if it's required that the kernel be upgraded 

no

> (I'm currently running 2.6.28.

nothing wrong with that

> I did download the sources (Should I have done that?),

yes, it doesn't hurt. Not required, but good to have

> but in the event
> it's not mandatory or anything to upgrade the kernel I'd really like to not
> have to recompile the thing. 

so don't.

You only *have* to upgrade the kernel if you want some feature the current one 
in use does not support

> Related, however, if I do recompile it and
> decide to do so with genkernel, 

Yuck. I tell people to stay away from that thing.

Just learn how to do it yourself. It's not hard, you get only what you want, 
and there are thousands of howtos all over the net

> will it respect the settings I've compiled
> into 2.6.28 or will they need to be reset again before 2.6.29 is compiled?

No. Not unless you give it the old config to use. IIRC it has some feature to 
use the config for the currently running kernel (/proc/config.gz) if the 
running kernel supports it. But I could be may off course here too.

> thanks for any information on the subject.

You'll get MUCH better answers by reading the kernel compile guide in the docs 
section of gentoo.org. Your post implies that you have not read it, as all 
your questions are answered in it. Knowledgeable folks here will give you the 
same answers, so just read the doc instead...

-- 
alan dot mckinnon at gmail dot com

Re: [gentoo-user] Kernel upgrade question: is it adviseable?

[Dale]

Alan McKinnon wrote:
> On Wednesday 03 June 2009 17:43:56 James Homuth wrote:
>   
>> Related, however, if I do recompile it and
>> decide to do so with genkernel, 
>>     
>
> Yuck. I tell people to stay away from that thing.
>
> Just learn how to do it yourself. It's not hard, you get only what you want, 
> and there are thousands of howtos all over the net
>   

I agree with this big time.  Both parts.

>   
>> will it respect the settings I've compiled
>> into 2.6.28 or will they need to be reset again before 2.6.29 is compiled?
>>     
>
> No. Not unless you give it the old config to use. IIRC it has some feature to 
> use the config for the currently running kernel (/proc/config.gz) if the 
> running kernel supports it. But I could be may off course here too.
>   

Why not copy the config from the old kernel over and run make
oldconfig?  May need to do some cleaning after genkernel tho.

>   
>> thanks for any information on the subject.
>>     
>
> You'll get MUCH better answers by reading the kernel compile guide in the docs 
> section of gentoo.org. Your post implies that you have not read it, as all 
> your questions are answered in it. Knowledgeable folks here will give you the 
> same answers, so just read the doc instead...
>
>   

I would agree with Alan here.  Learn to compile your own kernel.  It is
not nearly as bad as you may think.  If you use grub, just save the old
kernel you are using now.  If the boot fails, reboot, edit the grub boot
line and use the old kernel.  Heck, I keep at least 2 working kernels
here and during testing, I may have a dozen or more.  Grub is wonderful
when testing kernels. 

Curious to know a what to know which kernel is which, check this out:

root@smoker / # ls /boot/bzImage-2.6.2*
-rw-r--r-- 1 root root 2460088 Jan  2 20:13 /boot/bzImage-2.6.23-r8-7
-rw-r--r-- 1 root root 2463768 Apr 16 17:10 /boot/bzImage-2.6.23-r8-8
-rw-r--r-- 1 root root 2347324 May 16 12:09 /boot/bzImage-2.6.25-r9-1
-rw-r--r-- 1 root root 2347356 May 18 07:59 /boot/bzImage-2.6.25-r9-2
-rw-r--r-- 1 root root 2352956 May 23 09:51 /boot/bzImage-2.6.25-r9-3
-rw-r--r-- 1 root root 2370876 May 27 11:01 /boot/bzImage-2.6.25-r9-4
root@smoker / #

I know what version the sources are and what local version I compiled,
the number on the very end where each compile goes up one number.  I
been using Linux for years, notice it took me 4 tries to get my current
kernel working.  The last fix was USB, sort of missed the drivers for
that.  lol  I still keep my old trusty 2.6.23.  It took me 8 tries to
get that one perfected.  I say all that so you know you may not get it
perfect the very first time.

Hope that helps.

Dale

:-)  :-) 

Re: [gentoo-user] Kernel upgrade question: is it adviseable?

[Alan McKinnon]

On Wednesday 03 June 2009 18:39:56 Dale wrote:
> >> will it respect the settings I've compiled
> >> into 2.6.28 or will they need to be reset again before 2.6.29 is
> >> compiled? 
> >
> > No. Not unless you give it the old config to use. IIRC it has some
> > feature to use the config for the currently running kernel
> > (/proc/config.gz) if the running kernel supports it. But I could be may
> > off course here too. 
>
> Why not copy the config from the old kernel over and run make
> oldconfig?  May need to do some cleaning after genkernel tho.

That's the correct way :-)

But the OP asked if there was some magic way to get genkernel to use the same 
config as #SOME_OTHER_KERNEL.

Which of course makes no sense as there can be multiple versions and configs 
present.

The small remaining part of me that is still mostly unaffected by the onset of 
senility seems to remember genkernel being able to do something expressed as:

zcat /proc/config.gz > /usr/src/linux/.config
genkernel [....]

Which I suppose is a reasonable thing for an app like genkernel to do.
But I could also just be imagining it. It happens :-)


-- 
alan dot mckinnon at gmail dot com

Re: [gentoo-user] Kernel upgrade question: is it adviseable?

[Dale]

Alan McKinnon wrote:
> On Wednesday 03 June 2009 18:39:56 Dale wrote:
>   
>> Why not copy the config from the old kernel over and run make
>> oldconfig?  May need to do some cleaning after genkernel tho.
>>     
>
> That's the correct way :-)
>
> But the OP asked if there was some magic way to get genkernel to use the same 
> config as #SOME_OTHER_KERNEL.
>
> Which of course makes no sense as there can be multiple versions and configs 
> present.
>
> The small remaining part of me that is still mostly unaffected by the onset of 
> senility seems to remember genkernel being able to do something expressed as:
>
> zcat /proc/config.gz > /usr/src/linux/.config
> genkernel [....]
>
> Which I suppose is a reasonable thing for an app like genkernel to do.
> But I could also just be imagining it. It happens :-)
>
>
>   

True, I did go a little off base.  I did try genkernel once a long time
ago.  It included things for hardware I didn't have then omitted the
driver for my IDE chipset, did include that slow as crap generic tho. 
Anyway, to me, genkernel is a waste of time.  This is Gentoo, we want
only what we need and not one bit more.

Dale

:-)  :-)

Re: [gentoo-user] Kernel upgrade question: is it adviseable?

[Rumen Yotov]

On (03/06/09 15:40) Dale wrote:
> Alan McKinnon wrote:
> > On Wednesday 03 June 2009 18:39:56 Dale wrote:
> >   
> >> Why not copy the config from the old kernel over and run make
> >> oldconfig?  May need to do some cleaning after genkernel tho.
> >>     
> >
> > That's the correct way :-)
> >
> > But the OP asked if there was some magic way to get genkernel to use the same 
> > config as #SOME_OTHER_KERNEL.
> >
> > Which of course makes no sense as there can be multiple versions and configs 
> > present.
> >
> > The small remaining part of me that is still mostly unaffected by the onset of 
> > senility seems to remember genkernel being able to do something expressed as:
> >
> > zcat /proc/config.gz > /usr/src/linux/.config
> > genkernel [....]
> >
> > Which I suppose is a reasonable thing for an app like genkernel to do.
> > But I could also just be imagining it. It happens :-)
> >
> >
> >   
> 
> True, I did go a little off base.  I did try genkernel once a long time
> ago.  It included things for hardware I didn't have then omitted the
> driver for my IDE chipset, did include that slow as crap generic tho. 
> Anyway, to me, genkernel is a waste of time.  This is Gentoo, we want
> only what we need and not one bit more.
> 
> Dale
> 
> :-)  :-)
>
Hi,

genkernel uses a default config-file, check
/usr/share/genkernel/arch/x86/kernel-config.
i've backed it up, changing it to current .config.
Works always (haven't used it recently though).
HTH, Rumen