[ltp] From Jiang: recoverying partition

[linux-thinkpad@linux-thinkpad.org]

Quoting Jiang Qian <qian2@fas.harvard.edu>:

> Hi Joe:
> Thanks for the advice. I'll try that.
>
> After I do that(presumably I will can use accessIBM button to get into
> recovery console), would I then boot straight to windows partition? How
> do I then boot to linux partition? I ask this because I have multiple
> linux kernels to boot with grub before.

Yes, you would boot straight into Windows. I'll address the other 
questions, as
best I can, farther down...

> Do I need to reinstall Grub somewhere, say somewhere on my linux
> partition? Or I can boot using NTLDR into multiple linux partitions?

Since you say you have multiple linux kernels to boot, I believe you do 
need to
have GRUB installed on your linux partition. I'm not an expert on NTLDR, but I
don't think it can manage booting different kernels. I've never been in your
exact situation before, but the logical approach seems to me:

1. While GRUB is still on the MBR and you are still booting into Linux, 
install
GRUB to the Linux partition. See below for instructions. Also back up any
important data, just in case.

2. Do the "FIXMBR" and "FIXBOOT" commands, which will (should?) restore NTLDR
and get you back into booting Windows. Hopefully the restore partition should
be working again at this point.

3. Configure NTLDR to give you the option of either booting Windows or calling
GRUB, which will let you choose which kernel to boot. If you do some Googling
for "ntldr linux dual boot," you'll find a number of guides on how to set up
NTLDR. I also wrote something about this just a few days ago; it should be in
the list archives.

> And pardon me for asking too much, what do I need to do beforehand in
> order to prepare if things goes wrong I can at least recover to my
> current working configuration, which is grub booting all?

If things go wrong, you should be able to use an Ubuntu or Knoppix LiveCD to
rewrite GRUB to the MBR. You should probably keep a copy of your GRUB
configuration file handy, too. Different distros store it in different places
and give it different names. In Ubuntu (and, I assume, Debian) it's
/boot/grub/menu.lst. And, of course, back up all personal files, just in case
things go REALLY wrong...

> Do I need to
> dd something to save somewhere on my disk or I just need to reinstall
> grub? How do I reinstall grub from, say,ubuntu installation disk?

These aren't my directions. I got them from "wernst" on the Ubuntu forums:

<begin quote>

How to Restore the Grub Menu after a Re-Ghosting:

1. Boot from a Live CD, like Ubuntu Live, Knoppix, Mepis, or similar.

2. Open a Terminal. Go SuperUser (that is, type "su"). Enter root passwords as
necessary.

3. Type "grub" which makes a GRUB prompt appear.

4. Type "find /boot/grub/stage1". You'll get a response like "(hd0)" or in my
case "(hd0,3)". Use whatever your computer spits out for the following lines.

5. Type "root (hd0,3)".

6. Type "setup (hd0,3)". This is key. Other instructions say to use 
"(hd0)", and
that's fine if you want to write GRUB to the MBR. If you want to write it to
your linux root partition, then you want the number after the comma, such as
"(hd0,3)".

7. Type "quit".

8. Restart the system. Remove the bootable CD.

<end quote>

I've never had to reinstall GRUB, so I can't guarantee that those instructions
are accurate, but they look reasonable.

> My final question is: anyone did this or somewhere on the internet I
> can read about, say dual booting using ntldr?

Yep, as I said earlier, Googling for variatins of "ntldr linux dual boot" will
take you to a lot of good guides. It's fairly straightforward, but I won't
repeat it here, since others have already done a much better job than I would
do.

> Thank you indeed.
>
> Jiang

You're welcome, let me know how it turns out. Hope this is helpful.

Joe