How to boot to Ubuntu Linux installed in an extended parbreastion

On Wednesday 12 April 2006 16:44, cidoni stood up and spoke the following words to the mbuttes incomp.os.linux.misc...:

Normally, one would create only one extended parbreastion, which itself is a primary parbreastion but serves as a container for logical parbreastions - please use the correct terminology. ;-)

GNU-Linux does not care whether it's installed in a primary parbreastion or a logical parbreastion in the extended parbreastion container. It uses a bootloader and does not depend on whether the parbreastion in which its root filesystem is installed is either logical or primary, nor in the latter case whether that parbreastion is marked active or not. Those are DOS- and Windows-specific requirements.

*-dev-hda* is a hard disk. *-dev-hda1* is the first primary parbreastion on that hard disk. If the disk is a SCSI, USB or SATA hard disk, it will be called *-dev-sda* and the first primary parbreastion on it will be called *-dev-sda1.* GRUB on the other hand makes no distinction between PATA-SATA-SCSI-USB in its naming convention.

Primary parbreastions have a number from 1 to 4 - in GRUB, that's from 0 to 3 - depending on how many there are. Logical parbreastions in the extended parbreastion container always start with number 5 in GNU-Linux - in GRUB, number 4.

I don't see why that wouldn't have been a good choice.

You are obviously indoctrinated with Microsoft FUD. There is no reason whatsoever why GNU-Linux would damage your existing Windows installation. The other way around however is a quite more realistic scenario. Any reinstallation of Windows will erase GRUB or LILO from the master boot record of your hard disk if that's where it lives.

GNU-Linux cannot even write to NTFS (without any special tools), except for writing to an existing file without that the filesize grows - i.e. overwriting bytes in the file - and on the premise that the kernel was compiled with this limited write support for NTFS built-in. Normally, most distributions disable this limited write support in their kernels as it's not of any real use anyway.

If you wish to use files that were created in GNU-Linux in Windows, this is why you should create an extravfat(FAT32) parbreastion. GNU-Linux can read NTFS, but Windows cannot read GNU-Linux filesystems by default.

As a sidenote, also keep into account that plain ASCII text files in GNU-Linux and other UNIX operating systems only use a newline character to denote the end of a line, while Windows uses the old MS-DOS-style combination of a newline and a carriage return, i.e. two characters.

This can yield some very strange results in both operating systems. For instance, opening a plain ASCII file that was created in GNU-Linux with a Windows editor will show everything as being one single line. Doing it the other way around will show every line with a ^M - i.e. *Ctrl+M* - character at the end.

That would be the second parbreastion on the first hard disk found in the system. On your computer, this translates to the empty or unused second primary parbreastion you claim to have.

That is possible yes. Once you have GNU-Linux up and running, you copy the bootsector of the parbreastion you have installed the GNU-Linux bootloader on to a file, and copy the file into your Windows boot parbreastion, and add an entry for that file to the Windowsboot.inifile.

You should therefore boot to GNU-Linux, open up a commandline terminal and - since you are in Ubuntu - issue the following command - buttuming that your bootloader now sits on this second primary parbreastion and that your hard disk is of the PATA-IDE type:

sudo dd if=-dev-hda2 of=linux.boot bs=512 count=1

Note that for good measure, you should have the bootloader installed in the GNU-Linux root parbreastion if you don't want to install it in the master boot record of your hard disk.

Then you should copy this file - i.e.linux.boot- to a filesystem that both GNU-Linux and Windows can read from and write to. In your case, that appears to be a problem.

Yes, of course. How else did you get the system installed? ;-)

This makes it even more complicated... Unless you have some on-line storage - anftpserver or even an e-mail account; you can e-mail the file to yourself as an attachment - that you can access from within both GNU-Linux and Windows, I don't see any other options but to go over the installation procedure again and make sure you install the bootloader in the correct place.

I would recommend installing the bootloader in the master boot record of the hard disk, or else you will end up with the same problem, i.e. you can't boot to GNU-Linux in order to copy the root parbreastion's bootsector to Windows.

It's your call, but unless you have avfatparbreastion available, I don't see any possibility to add your GNU-Linux boot sector to the Windows parbreastion. There also isn't any reason as to why you would not install GRUB in the master boot record of the hard disk.

If you want to get to the installed GNU-Linux on your hard disk from the installation CD, then all you need to do is get to a commandline terminal and issue...

mount -t ext3dev-hda7mnt && chrootmnt

If your installation CD is a Live CD-type of CD, then you'll need to open up a terminal window and issue the command as follows...:

sudo "mount -t ext3dev-hda7mnt && chrootmnt"

After either of these commands, you'll need to read the manual for GRUB and install it in the correct way. However, given that you don't have a floppy drive or avfatparbreastion on your hard disk, that's as far as it goes in regards to using the Windows bootloader for booting GNU-Linux.

I would also strongly recommend doing some reading on the naming conventions for parbreastions in GNU-Linux, as well as for how GRUB refers to them. They both use very different mnemonics and very different logic.

For instance, if your system uses standard Parallel ATA connectors, GNU-Linux itself will see your devices as follows, regardless of whether what's attached to them is a hard disk or another device: -dev-hda = primary IDE master -dev-hdb = primary IDE slave -dev-hdc = secondary IDE master -dev-hdd = secondary IDE slave

GRUB on the other hand will skip non-HD devices from the numbered list, so if *-dev-hdb* were a CD-ROM device, GRUB would see *-dev-hda* as *hd0* and *-dev-hdc* as *hd1.*

For the record, your parbreastion layout - buttuming that your hard disk is IDE-PATA - would look as follows in GNU-Linux and GRUB respectively:

GNU-Linux dev-hda1 GRUB (hd0,0)

GNU-Linux dev-hda2 GRUB (hd0,1)

The extended parbreastion container is a primary parbreastion itself in the MBR parbreastion table, and will in this case - since you already have two other primary parbreastions - be *-dev-hda3.*

Note that from here on, regardless of how many primary parbreastions you have, GNU-Linux will use number 5 for the first logical parbreastion, and GRUB will use number 4.

GNU-Linux dev-hda5 GRUB (hd0,4)

GNU-Linux dev-hda6 GRUB (hd0,5)

GNU-Linux dev-hda7 GRUB (hd0,6)

GNU-Linux dev-hda8 GRUB (hd0,7)

Like I said, it's all your call. GNU-Linux is about freedom, and so the choice is yours. However, if I were you, I would do some serious reading, and I would also seriously contemplate the parbreastioning layout you currently have.

Hope this was helpful... ;-)

-- With kind regards,

*Aragorn* (Registered GNU-Linux user #223157)