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From: Lew Pitcher on 18 Jun 2010 13:05
On June 18, 2010 12:29, in alt.os.linux.suse, houghi(a)houghi.org.invalid
wrote:

> Abbey Somebody wrote:
>> On Thu, 17 Jun 2010 21:57:55 -0400, LSMFT <boleyn7(a)aol.com> wrote:
>>
>>>Why does Linux label /dev/sda to MSDOS?
>>
>>
>> Linux "names" devices. It doesn't "label" them.
>
> All interesting, but that does not realy answer the question of the GP.
> He is talking about the partition table name.
> As root:
> penne:~ # parted /dev/sde print
> Model: ATA ST31500341AS (scsi)
> Disk /dev/sde: 1500GB
> Sector size (logical/physical): 512B/512B
> Partition Table: msdos
> Number Start End Size Type File system Flags
> 1 32.3kB 1500GB 1500GB primary ext3 type=83
>
> See the line "Partition Table: msdos"? That is what we are talking
> about.

OK, here's the scoop.

There are a wide and unending variety of ways that an operating system can
divide up the space on a single disk device into logical containers.

Not all operating systems use the same methods for dividing that disk space
up. In fact, several OS' have conflicting and mutually-exclusive methods of
dividing disk space.

For instance, for MSDOS (and it's follow-on operating systems), Microsoft
(probably with assistance from IBM) decided to carry the "logical
container" information for each drive in the last 64 octets of the 1st
(512-octet) "sector" of the disk. (With later extensions placed in other
parts of the disk).

Other operating systems store different information for "logical containers"
in different places on the disk.

Linux, which works with disks from all these environments, must be able to
determine /which/ partitioning method is used, and be able to interpret the
partitioning information stored in /that/ method.

The first utility that sees this information is typically the boot loader
(as it has to both live within and decypher for itself the specific
partitioning method used on the drives under it's control). Both Grub and
Lilo offer mnemonics to their end-users indicating /which/ partitioning
method has been used on /which/ media.

For the MSDOS-style partitioning method, the term that Grub, Lilo, and Linux
use is "MSDOS". For Solaris-origined disks, the term is "Sun". For BSD
volumes, "BSD". For Apple Macintosh disks, "Mac". And so on.

So, if Grub or Lilo or some other Linux tool tells you that your /dev/sda
is "MSDOS", it is saying that that device is /partitioned/ using the
MSDOS-style partitioning method. If it says that the device is "Sun", then
the device is /partitioned/ using the Sun Solaris partitioning method. And
so on.

> If, for whatever reason, you want to change that. That is possible using
> gparted or if you prefere CLI parted. From `man parted`:
> mklabel label-type
> Create a new disklabel (partition table) of label-type.
> label-type should be one of "bsd", "dvh", "gpt", "loop",
> "mac", "msdos", "pc98", or "sun"
HTH
--
Lew Pitcher
Master Codewright & JOAT-in-training | Registered Linux User #112576
Me: http://pitcher.digitalfreehold.ca/ | Just Linux: http://justlinux.ca/
---------- Slackware - Because I know what I'm doing. ------


From: Archimedes' Lever on 18 Jun 2010 13:29
On Fri, 18 Jun 2010 18:29:50 +0200, houghi <houghi(a)houghi.org.invalid>
wrote:

>Abbey Somebody wrote:
>> On Thu, 17 Jun 2010 21:57:55 -0400, LSMFT <boleyn7(a)aol.com> wrote:
>>
>>>Why does Linux label /dev/sda to MSDOS?
>>
>>
>> Linux "names" devices. It doesn't "label" them.
>
>All interesting, but that does not realy answer the question of the GP.
>He is talking about the partition table name.
>As root:
>penne:~ # parted /dev/sde print
>Model: ATA ST31500341AS (scsi)
>Disk /dev/sde: 1500GB
>Sector size (logical/physical): 512B/512B
>Partition Table: msdos
>Number Start End Size Type File system Flags
> 1 32.3kB 1500GB 1500GB primary ext3 type=83
>
>See the line "Partition Table: msdos"? That is what we are talking
>about.
>
>If, for whatever reason, you want to change that. That is possible using
>gparted or if you prefere CLI parted. From `man parted`:
> mklabel label-type
> Create a new disklabel (partition table) of label-type.
> label-type should be one of "bsd", "dvh", "gpt", "loop",
> "mac", "msdos", "pc98", or "sun"
>

The moment you relabel (partition label) any drive differently than it
was, the drive partition tables get reset/dumped. At least that is my
experience with some types.
From: Jan Kandziora on 18 Jun 2010 16:48
LSMFT schrieb:
>
> Why isn't there a Linux or Unix type?
>
Because the PC BIOS won't boot an MBR that is too different from the "MSDOS"
type and a MS-Windows parallel install would do neither.

Kind regards

Jan
From: LSMFT on 18 Jun 2010 17:55
Archimedes' Lever wrote:
> On Fri, 18 Jun 2010 12:29:27 -0400, LSMFT<boleyn7(a)aol.com> wrote:
>
>> While installing Opensuse 11.3 RC1 I distinctly saw the installation
>> software mark the virtual drive /dev/hda as MSDOS.
>
> virtual drive?
>
> If it /dev/hda, it isn't virtual. It is physical.

The software doesn't know the difference. It's the same.

--
LSMFT

I haven't spoken to my wife in 18 months.
I don't like to interrupt her.
From: Archimedes' Lever on 18 Jun 2010 19:00
On Fri, 18 Jun 2010 17:55:50 -0400, LSMFT <boleyn7(a)aol.com> wrote:

>Archimedes' Lever wrote:
>> On Fri, 18 Jun 2010 12:29:27 -0400, LSMFT<boleyn7(a)aol.com> wrote:
>>
>>> While installing Opensuse 11.3 RC1 I distinctly saw the installation
>>> software mark the virtual drive /dev/hda as MSDOS.
>>
>> virtual drive?
>>
>> If it /dev/hda, it isn't virtual. It is physical.
>
>The software doesn't know the difference. It's the same.


It obviously does. It "sees" the MBR partitioning schema, and reports
msdos to the observer. The drive itself gets no actual label edited into
it.

If the drive had GPT schema, it would report a different type.
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