Dale,

Friday, April 13, 2012, 10:35:43 PM, you wrote:

>> I have ran into a issue here. I copied everything over to sdb, my temp
>> drive. When I try to boot it, it still boots from sda which is the
>> primary drive. I can not get it to boot from the copy. I did update
>> the fstab file to point to the new sdb partitions, I use labels for that
>> and they have different names. I also edited grub and told it root was
>> sdb2. When I boot, everything mounted is sda.
>>
>> Those are from the copy. Here is grub:
>>
>> title=Initramfs-new_drive
>> root (hd0,0)
>> kernel /bzImage-3.3.1-1 root=/dev/sdb2 init=/sbin/init nox
>> initrd /initramfs-3.3.1-1-tmp.img

if you want to boot from /dev/sdb, why do you tell grub
to use (hd0,0), which usually maps to /dev/sda1?

I'd expect to see root (hd1,0) in there somewhere.

Depending on boot flags and BIOS settings, you might still
be using the MBR on /dev/sda.

When I migrated a client's data over to a new disk a while
ago, I basically used "tar cf - /sda | tar xf - -C /sdb" and
then switched SATA cables before rebooting. The former /dev/sdb
became /dev/sda and everything was fine.

s.

>>
>> I have done this in the past and it worked but not now. Is this the
>> init thingy mounting sda stuff and then Gentoo carries on from there?
>> If so, how do I tell the init thingy to point to sdb stuff?
>>
>> Thoughts?
>>
>> Dale
>>
>> :-) :-)
>>


D> OK. I thought of something else to try. I created a new grub entry.
D> This is a plain entry with no init thingy at all. It looks like this:

D> title Gentoo no init tmp drive
D> kernel (hd0,0)/bzImage-3.3.1-1 root=/dev/sdb2 nox

D> Simple but it still boots the sda drive instead of the sdb drive. What
D> am I missing here? I looked in dmesg, the root=/dev/sdb2 line is in
D> there so grub passes it on.

D> This is weird. I need ideas folks. I'm running out of things to try.

D> Dale

D> :-) :-)




--
Stefan Schmiedl
EDV-Beratung Schmiedl, Berghangstr. 5, D-93413 Cham
im Büro: 09971 9966 989, am Handy: 0160 9981 6278

"This is why Science and Mathematics are still much fun:
You discover things that seem impossible to be true
and then get to figure out why it's impossible for them not to be."

-- Vi Hart: Spirals, Fibonacci, and Being a Plant, Part 3

Dale,

Saturday, April 14, 2012, 5:46:44 AM, you wrote:

D> Stefan Schmiedl wrote:
>> I'd expect to see root (hd1,0) in there somewhere.

D> I tried changing the root line and it still booted sda. Also, note that
D> I also tried a grub entry that doesn't even have a root line. It just
D> points directly to sdb.

D>From what I have always been told, the root line points to grub not the
D> root partition of the OS. Those are two different things. Correct me
D> if I am wrong here. That's the way I have always been told.

That is correct, "root (hdx,y)" points to partition y on drive x, where
the kernel is to be found, i.e. the root path for the "kernel" line.
The kernel uses its root=/dev/whatever to set up the root for the linux
environment.

D> I'm using grub legacy here.

me too. And the last time I tried, changing the root line made grub boot
from the other disk. Have you tried editing this line in grub's editor
during boot?

s.