-------- Message original --------
To my opinion, there is no way to swich from distribution "A" to
distribution "B". Grub is no GNU/Linux application, it's a bootloader
which runs when there is still noone else running. However, I may be
wrong, and if somebody else says it's possible to switch from a
distribution to another one, do what he will instruct you to do.
Now, it seems to me that the best we can do is trying to understand
what's wrong with your configuration. So, please, post the result of the
Le 17/03/2012 22:16, Peter Van Wieren a écrit :
> After the entire boot process is complete, and an OS is running normally, I was wondering if it was possible to simply execute a new kernel/initrd which would replace the current one.
> An analogy would be the "exec" family of system calls in unix. These calls cause the current process to be replaced by another. I would like to replace the currently running kernel/initrd/root filesystem with another without powering down the host or changing the master boot record.
> --- On Sat, 3/17/12, Arbiel Perlacremaz<address@hidden> wrote:
>> From: Arbiel Perlacremaz<address@hidden>
>> Subject: Re: is booting an OS without power cycling a host possible?
>> To: "Peter Van Wieren"<address@hidden>, address@hidden
>> Date: Saturday, March 17, 2012, 4:58 PM
>> I do not quite understand what you
>> want to do. Is that that, in a first
>> stage, you want to boot distribution A, and then, in a
>> second stage,
>> switch to distribution B, as though you had directly booted
>> distribution B.
>> This is definitely not possible.
>> Now, there is no difficulty to have grub2 (for Grub Legacy,
>> you may be
>> speaking of, I really don't know) residing on a drive to
>> boot a
>> distribution located on another drive.
>> So, please, clarify the situation you are in.
>> Le 17/03/2012 19:33, Peter Van Wieren a écrit :
>>> I have a host with linux distribution "A". The
>> host is presently running "A", and has already been started
>> by grub. There exists, on a second hard disk drive,
>> linux distribution "B" is installed but not mounted.
>>> I hoped I could transition from "A" to "B", without
>> power cycling the host or editing the MBR, by running grub
>> from the command line as root. In a root shell I
>> started grub and planned to issue the commands:
>>> 1) root (hd1,0)
>>> 2) kernel .... vmlinuz
>>> 3) initrd ....
>>> 4) boot
>>> My hope was that distribution "B" would boot, and "A"
>> would somehow be abolished. I do not know for sure if
>> the above is supposed to even be possible or not. Can
>> it be done?
>>> I made it to step #3. The trouble is the "initrd"
>> command returns "Error 16: inconsistent filesystem"
>>> P.S. Why would I want to do this? Answer: I threw
>> my old USB keyboard in the trash, and replaced it with a new
>> one. It was all well and good, until I found that the
>> new keyboard doesn't work at all during the BIOS or GRUB
>> stages -- the new keyboard only works after the OS has been
>> booted. Thus if I change the default option in
>> grub.conf to "B" and something doesn't work, my host will
>> become completely useless until such a time as I can locate
>> a 2002 era USB keyboard -- which in theory should work in
>> the BIOS and GRUB stages.
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