Re: How To Write Extended Partition Tables from GRUB? - sburtchin Feb 1, 2007; 11:51pm

[sburtchin]

NOTE: Adding message of sburtchin Feb 1, 2007; 11:51pm to Nabble thread.


----- Original Message ----- 
From: "adrian15" <address@hidden>
To: "sburtchin" <address@hidden>
Cc: <address@hidden>
Sent: Thursday, February 01, 2007 12:52 PM
Subject: Re: How To Write Extended Partition Tables from GRUB?


> sburtchin escribió:
> > Another situation deals with data recovery.  If the partition tables
happen
> > to become corrupted, fixing these errors can be the first and best step
to
> > data recovery.  There are tools for doing this, but a much quicker
approach
> > would be to add a "Restore All Partition Tables" selection to the GRUB
menu.
> > This is easily scripted in "menu.lst" using a combination of "partnew"
and
> > "eptedit" commands.
> >
> This restore All Partition Tables selection how would it be implemented...
>
You would first have to get the information about your partitions.
PowerQuest's PARTINFO will create a text file for you.  I created a
spreadsheet because I have a lot of partitions (see attached image - the
highlighted primary partitions are for the standard MPT, the rest can be
swapped for the standard ones to boot other os's).  Then copy the data into
menu.lst and insert "partnew" and "eptedit" at the appropriate places (I
would suggest converting partinfo.txt to a spreadsheet.  Then you can select
just the columns you need to put into menu.lst --- saving yourself a lot of
unnecessary editing).

After a minimal amount of editing, my "Restore All Partition Tables" section
of menu.lst would be as in the attached text file.  Starting with the
information from the spreadsheet, this took me about 15 minutes to create
(first time), but now that I know how to do it, I could probably do it in 5.

Selecting this boot item in the GRUB menu would do exactly what it says!

> on the running system you run an script that saves all your partition
> data into a menu.lst that uses that eptedit command and then...
>
You run a free (or other) program like PARTINFO and then you edit the
information as explained above to create the boot item in menu.lst.

> you can burn this menu.lst into a grub cdrom so that you can use
>
Yes!!! - if you can't access the menu.lst on the HDD.

> FOR ONLY your computer in a future ?
>
Not exactly - Suppose you are managing an IT department and you want to roll
out 200 new computers all with identical HDD's.  You could partition all of
them in the time it takes to boot to CD and hit enter!  I know there are
other ways of doing this (multicasting), but if later - any one of these 200
computers would have its partition tables corrupted, you could restore all
the partition tables just as fast.  I'm not aware of any other tools that
would do it this fast.

> Is that your idea ?
>
>
> adrian15
>
That was not my idea at all originally, but I am excited to see that my new
function has a purpose that would interest others.  I actually only thought
of using it this way as an afterthought while I was explaining what I wanted
it for back on November 18.  Serendipity at work!

I would definitely want to use it as in the attached text file if my
partition tables were ever corrupted, but I originally wanted it so I could
define extended partitions with the same starting cylinder, but with
different ending cylinders (because some older os's can only see the first
1024 cylinders - ref. my November 18 reply).



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