Linux support for Microsoft dynamic disks?

Linux support for Microsoft dynamic disks?

[Anton Altaparmakov]

Hi all,

Is anyone working on supporting the dynamic disk format introduced with 
Windows 2000? If not, does anyone have the specs / any detailed info on the 
on disk structures involved?

Cheers,

         Anton


-- 
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Linux NTFS Maintainer / WWW: http://sourceforge.net/projects/linux-ntfs/
ICQ: 8561279 / WWW: http://www-stu.christs.cam.ac.uk/~aia21/

Re: Linux support for Microsoft dynamic disks?

[Guest section DW]

On Sun, May 13, 2001 at 12:06:03AM +0100, Anton Altaparmakov wrote:

> Is anyone working on supporting the dynamic disk format introduced with 
> Windows 2000? If not, does anyone have the specs / any detailed info on the 
> on disk structures involved?

I once collected some stuff from the Microsoft Knowledge Base.
In
	http://www.win.tue.nl/~aeb/partitions/partition_types-1.html
(hint: additions and corrections are welcome!)
you find partition type 42 that marks a partition table as legacy.

Unfortunately I do not have Windows 2000. (But I have DOS 4.01 :-)

Andries

Re: Linux support for Microsoft dynamic disks?

[Jeff V. Merkey]

On Sun, May 13, 2001 at 12:06:03AM +0100, Anton Altaparmakov wrote:
> Hi all,
> 
> Is anyone working on supporting the dynamic disk format introduced with 
> Windows 2000? If not, does anyone have the specs / any detailed info on the 
> on disk structures involved?
> 
> Cheers,
> 
>          Anton

Anton,

What is your specific question?

Jeff

> 
> 
> -- 
> Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
> Linux NTFS Maintainer / WWW: http://sourceforge.net/projects/linux-ntfs/
> ICQ: 8561279 / WWW: http://www-stu.christs.cam.ac.uk/~aia21/
> 
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Re: Linux support for Microsoft dynamic disks?

[Guest section DW]

On Sat, May 12, 2001 at 08:34:45PM -0600, Jeff V. Merkey wrote:

> What is your specific question?

Well, my specific question would be: enough information to support
mounting filesystems that live on a dynamic disk.

Andries

Re: Linux support for Microsoft dynamic disks?

[Art Boulatov]

On Sunday 13 May 2001 02:46 pm, Guest section DW wrote:
> On Sat, May 12, 2001 at 08:34:45PM -0600, Jeff V. Merkey wrote:
> > What is your specific question?
>
> Well, my specific question would be: enough information to support
> mounting filesystems that live on a dynamic disk.
>
> Andries

Understanding the layout of a dynamic disk is just a part of the problem
as far as I can see it.
What if I have two (three,four) dynamic disks with volumes organized into a 
software stripe (raid0) under Windows?
There must be an implementation of MS' software raid in the linux kernel in 
order to access that "striped filesystem"  under linux, I'm I right?

Art.

Re: Linux support for Microsoft dynamic disks?

[Andreas Dilger]

Art writes:
> Understanding the layout of a dynamic disk is just a part of the problem
> as far as I can see it.
> What if I have two (three,four) dynamic disks with volumes organized into a 
> software stripe (raid0) under Windows?
> There must be an implementation of MS' software raid in the linux kernel in 
> order to access that "striped filesystem"  under linux, I'm I right?

I think the correct place to start implementing this is in the framework
of the EVMS project (http://sourceforge.net/projects/evms).  It is doing
the work of a generalized block-remapping driver for Linux.  They already
have working Linux LVM kernel drivers, along with MS-DOS partition code,
etc.  Adding in the NT dynamic disk remapping would probably be welcome.

Cheers, Andreas
-- 
Andreas Dilger  \ "If a man ate a pound of pasta and a pound of antipasto,
                 \  would they cancel out, leaving him still hungry?"
http://www-mddsp.enel.ucalgary.ca/People/adilger/               -- Dogbert

Re: Linux support for Microsoft dynamic disks?

[Anton Altaparmakov]

At 19:15 13/05/2001, Art Boulatov wrote:
>On Sunday 13 May 2001 02:46 pm, Guest section DW wrote:
> > On Sat, May 12, 2001 at 08:34:45PM -0600, Jeff V. Merkey wrote:
> > > What is your specific question?
> >
> > Well, my specific question would be: enough information to support
> > mounting filesystems that live on a dynamic disk.
>
>Understanding the layout of a dynamic disk is just a part of the problem
>as far as I can see it.
>What if I have two (three,four) dynamic disks with volumes organized into a
>software stripe (raid0) under Windows?
>There must be an implementation of MS' software raid in the linux kernel in
>order to access that "striped filesystem"  under linux, I'm I right?

That is a completely separate issue since NT4 software raid also exists but 
doesn't use dynamic disks at all. The existing md driver in Linux can be 
modified to make this work. No need for a full rewrite. There are problems 
with it at the moment which make it not work for ntfs software raid but 
they can be solved. It's just not on anyones high priority list at the 
moment...

Anton


-- 
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Linux NTFS Maintainer / WWW: http://sourceforge.net/projects/linux-ntfs/
ICQ: 8561279 / WWW: http://www-stu.christs.cam.ac.uk/~aia21/

Re: Linux support for Microsoft dynamic disks?

[Anton Altaparmakov]

At 03:34 13/05/2001, Jeff V. Merkey wrote:
>On Sun, May 13, 2001 at 12:06:03AM +0100, Anton Altaparmakov wrote:
> > Is anyone working on supporting the dynamic disk format introduced with
> > Windows 2000? If not, does anyone have the specs / any detailed info on 
> the
> > on disk structures involved?
>
>What is your specific question?

My question is quite generic: What is the on disk layout of Win2k's dynamic 
disk, i.e. Logical Disk Manager (LDM) database structures? - The article 
"Inside Storage Managment, Part 2" by Mark Russinovich in Windows 2000 
magazine (full text available freely at: 
http://www.win2000mag.com/Articles/Index.cfm?ArticleID=8303) describes in 
detail the logical layout of the LDM database, but it doesn't cover enough 
detail to go off and implement it in Linux (without a certain amount of 
reverse engineering).

Linux needs to understand the LDM database in order to support dual-boot 
Win2k (or XP) and Linux configurations where there are one or more dynamic 
disks present in the system and the user wants to access their NTFS 
partitions residing on the dynamic disk(s) from Linux.

Just saying "Don't use dynamic disks if you want to use Linux" is IMHO a 
Bad Thing(TM) as a user might have bought a computer with Win2k 
preinstalled on a dynamic disk or, even worse, might have been using Win2k 
only previously, and then the user wants to also install Linux on it. In 
these cases the user would have to reformat the whole system and start from 
scratch unless Linux supports dynamic disks... Reinstalling Windows is a 
major PITA considering the number of reboots required and how slow Win2k 
boots. I recently upgraded a Win98 machine in my lab to Win2k and it took 
me around 5 hours to do with god knows how many reboots in between and 
constant user intervention required. Ugh!

Anton


-- 
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Linux NTFS Maintainer / WWW: http://sourceforge.net/projects/linux-ntfs/
ICQ: 8561279 / WWW: http://www-stu.christs.cam.ac.uk/~aia21/

Re: Linux support for Microsoft dynamic disks?

[mirabilos]

> Linux needs to understand the LDM database in order to support
dual-boot
> Win2k (or XP) and Linux configurations where there are one or more
dynamic
> disks present in the system and the user wants to access their NTFS
> partitions residing on the dynamic disk(s) from Linux.

I had (on a 2G disk) a NTFS, a FAT and some Linux partitions. It even
refused
to convert to dynamic disk. When it finally did, my Linux partitions
vanished.
You need this support to even be able to use linux on that disk... btw
that
is my largest HDD I have :(
So I now removed that crap, bought a laptop and use static disks. And
installed
some linux.

-mirabilos
--
EA F0 FF 00 F0 #$@%CARRIER LOST

Re: Linux support for Microsoft dynamic disks?

[Art Boulatov]

On Sunday 13 May 2001 03:15 pm, mirabilos wrote:

> ................
> I had (on a 2G disk) a NTFS, a FAT and some Linux partitions. It even
> refused
> to convert to dynamic disk. When it finally did, my Linux partitions
> vanished.
> You need this support to even be able to use linux on that disk... btw
> .........................

It is actiually possible to have both Linux and Windows 2000/Windows XP with 
dynamic disk on the same hard drive for now.

The thing is you have first to install Windows XP, leaving  required space 
for the Linux install, and convert the drive to dynamic disk.
When it is sucessfully converted you can reboot from linux floppy and "resize"
the last partition on the disk to the place where the free space actually 
begins.
Now it's possible to create some partitions here to install Linux.
The point is Windows still thinks there is an unpartioned space there,
where you just put your Linux distro :)

But thats not the option anyway,
and recognising dynamic disks would be a much better solution :). 

Art.

Re: Linux support for Microsoft dynamic disks?

[Mr. James W. Laferriere]

	Hello All , I see one very big gotcha here .  M$ doesn't want you
	to have a linux partition on the drive they fdo this by not
	recognising your ext2/ext3/JFS/... partition .
	The next real difficulty is going to be for those that already
	have a linux system setup and are going to try & install M$-LDM on
	their drives & BANG!  no more ext2/... .  A work around such as Art
	describes below is VERY much needed & needs to be posted in all
	the right places .
	As an aside linux-kernel/... are going to hear at least a half a
	years worth of noise about it .  Sorry about the noise .  JimL

On Sun, 13 May 2001, Art Boulatov wrote:

> On Sunday 13 May 2001 03:15 pm, mirabilos wrote:
>
> > ................
> > I had (on a 2G disk) a NTFS, a FAT and some Linux partitions. It even
> > refused
> > to convert to dynamic disk. When it finally did, my Linux partitions
> > vanished.
> > You need this support to even be able to use linux on that disk... btw
> > .........................
>
> It is actiually possible to have both Linux and Windows 2000/Windows XP with
> dynamic disk on the same hard drive for now.
>
> The thing is you have first to install Windows XP, leaving  required space
> for the Linux install, and convert the drive to dynamic disk.
> When it is sucessfully converted you can reboot from linux floppy and "resize"
> the last partition on the disk to the place where the free space actually
> begins.
> Now it's possible to create some partitions here to install Linux.
> The point is Windows still thinks there is an unpartioned space there,
> where you just put your Linux distro :)
>
> But thats not the option anyway,
> and recognising dynamic disks would be a much better solution :).
>
> Art.
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
>

       +----------------------------------------------------------------+
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       +----------------------------------------------------------------+

Re: Linux support for Microsoft dynamic disks?

[Anton Altaparmakov]

At 11:46 13/05/2001, Guest section DW wrote:
>On Sat, May 12, 2001 at 08:34:45PM -0600, Jeff V. Merkey wrote:
>
> > What is your specific question?
>
>Well, my specific question would be: enough information to support
>mounting filesystems that live on a dynamic disk.

Ok, much nicer phrased than mine. But that is effectively what I would like 
to know, too. (-:

Anton


-- 
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Linux NTFS Maintainer / WWW: http://sourceforge.net/projects/linux-ntfs/
ICQ: 8561279 / WWW: http://www-stu.christs.cam.ac.uk/~aia21/