seperate environments for different kernels

seperate environments for different kernels

[Younggyun Koh]

Hi,

i want to run linux 2.6.6 kernel, which needs upgrade of some system tools
such as module-init-tools and nfs-utils. but other guys using the same
machine with 2.4 kernel don't want me to upgrade them.

is there any way i can make different system tools installed when i boot
with the different kernel images other than mounting root directory to the
different partitions? (i can't create a new partition)

thank you,

			-Younggyun Koh (young@cc.gatech.edu)

Re: seperate environments for different kernels

[Rob]

On Saturday 29 May 2004 09:13 pm, Younggyun Koh wrote:
> Hi,
>
> i want to run linux 2.6.6 kernel, which needs upgrade of some system tools
> such as module-init-tools and nfs-utils. but other guys using the same
> machine with 2.4 kernel don't want me to upgrade them.
>
> is there any way i can make different system tools installed when i boot
> with the different kernel images other than mounting root directory to the
> different partitions? (i can't create a new partition)
>
> thank you,
>
> 			-Younggyun Koh (young@cc.gatech.edu)
> -
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i was thinking about this... my brute force idea:
make some very early init scripts manipulate a bunch of symlinks, based on the 
output of uname -r. you have a different kernel, it renames some dirs, and 
goes on as normal. in fact, you oughta be able to have a few separate init 
script kits that all run but immediately exit if their designated kernel 
isn't running, like  `uname -r`= "2.6.6-test1" || exit
 
-- 
Rob Couto [rpc@cafe4111.org]
computer safety tip: use only a non-conducting, static-free hammer.
--

Re: seperate environments for different kernels

[Rob]

On Saturday 29 May 2004 09:13 pm, Younggyun Koh wrote:
> Hi,
>
> i want to run linux 2.6.6 kernel, which needs upgrade of some system tools
> such as module-init-tools and nfs-utils. but other guys using the same
> machine with 2.4 kernel don't want me to upgrade them.
>

sorry, typo bug: that statement is actually 
[ `uname -r` == "2.x.x-this-script's-desired-version" ] || exit

and since mod-init-tools are in /, you may need to actually replace them all 
with wrapper scripts which call up the right one, passing all command-line 
arguments to the real one... you install the 2.4 utils, move them all (i.e., 
to *-2.4) then the same for 2.6, and make a script with the original name 
that calls the 2.6 binary when uname -r returns a 2.6 kernel, likewise with 
2.4, etc.

even easier: you may be able to get away with this hack:

mount --bind /some-dir/2.6-bin /bin
mount --bind /some-dir/2.6-lib /lib
mount --bind /some-dir/2.6-sbin /sbin
mount --bind /some-dir/2.6-etc /etc
and so on.

do this in a script that starts with that statement above, so that only when 
*your* kernel runs, it maps over the 2.4 kit without touching it.

-- 
Rob Couto [rpc@cafe4111.org]
computer safety tip: use only a non-conducting, static-free hammer.
--

Re: seperate environments for different kernels

[Andre Tomt]

Younggyun Koh wrote:

> Hi,
> 
> i want to run linux 2.6.6 kernel, which needs upgrade of some system tools
> such as module-init-tools and nfs-utils. but other guys using the same
> machine with 2.4 kernel don't want me to upgrade them.
> 
> is there any way i can make different system tools installed when i boot
> with the different kernel images other than mounting root directory to the
> different partitions? (i can't create a new partition)

Modern distributions handle this more or less transparently. 
module-init-tools can call on modutils if it sees you're running a 2.4 
kernel.

-- 
Cheers,
André Tomt