ATA Raid on a Dual Boot (Win 2K and Linux [kernel 2.6])?

ATA Raid on a Dual Boot (Win 2K and Linux [kernel 2.6])?

[Stefan Muenkner]

Hi,

lately my hard disks started reaching a fill level where I consider
buying some new ones.  Linux has been flawlessly running on a SW raid-1
for almost 5 years now (thanks a bunch to all the ones who contributed),
but I always felt the lack of having such a solution under win 2K.
Since there are some rather inexpensive (S-)ATA-Raid  cards around I
thought about buying one of those to finally mirror the Win-Partitions
(I know the cards suck re preformance and all the rest of it).  As far
as I know, using kernel 2.6 (probably SuSE 9.2/9.3), there will be only
dmraid supporting ataraid, but I actually could also live very well with
a sw-raid solution (in fact I did for quite some time) and not be seeing
the Windows partitions from Linux at all. So my question is the following:

Has anybody experience with the following setup:

- I would like to set up the two disks as a mirror raid set using the
ATA-Raid card.
- A reasonable portion of the raid-set will then be partionend and used
by windows.
- (Probably) I would actually use a DOS/Win based program to
pre-partition the rest of the mirrored disks for Linux
- the remaining Linux partitions will then be used as a SW-Raid-1 set
(with a LVM on top of it?).

As far as I know, Linux should be seeing all the partitions made for the
"hardware" raid windows setup as being separate partitions on the two
hard disks (identical layout). So I should be able to mirror them using
sw-raid.

Has anybody done that? Is there anything that looks like it will be
impossible to do? Any hardware I should avoid?

I am aware that I will probably do a lot of manual tweaking during the
first Linux install, but I think I can handle that :-).  Before buying
all that stuff and put in the effort it would be reassuring if I knew
it's feasible....

Thanks in advance,

  Stefan

Re: ATA Raid on a Dual Boot (Win 2K and Linux [kernel 2.6])?

[Joshua Baker-LePain]

On Thu, 28 Apr 2005 at 4:40pm, Stefan Muenkner wrote

> Has anybody experience with the following setup:
> 
> - I would like to set up the two disks as a mirror raid set using the
> ATA-Raid card.
> - A reasonable portion of the raid-set will then be partionend and used
> by windows.
> - (Probably) I would actually use a DOS/Win based program to
> pre-partition the rest of the mirrored disks for Linux
> - the remaining Linux partitions will then be used as a SW-Raid-1 set
> (with a LVM on top of it?).

If you're willing to pay a bit more, you could buy a "real" RAID card 
(e.g. a 3ware 8000 series) with support in both OSes.  Do a hardware 
mirror in the 3ware, and then both OSes will see a single drive via their 
native drivers.  A 8006-2 (2 port SATA) is $130 on buy.com.

-- 
Joshua Baker-LePain
Department of Biomedical Engineering
Duke University

Re: ATA Raid on a Dual Boot (Win 2K and Linux [kernel 2.6])?

[Stefan Muenkner]

> 
> If you're willing to pay a bit more, you could buy a "real" RAID card 
> (e.g. a 3ware 8000 series) with support in both OSes.  Do a hardware 
> mirror in the 3ware, and then both OSes will see a single drive via their 
> native drivers.  A 8006-2 (2 port SATA) is $130 on buy.com.
> 

My problem is: Here in Germany the cheapest 8006-2 I can get hold of is 
at just under 140 Euros (about $180) which is quite a bit more than I 
was actually thinking to invest. Well, I will consider it, technically 
it is a sweet solution....

Thanks,

   Stefan

Re: ATA Raid on a Dual Boot (Win 2K and Linux [kernel 2.6])?

[Luca Berra]

On Thu, Apr 28, 2005 at 04:40:22PM +0200, Stefan Muenkner wrote:
>As far as I know, Linux should be seeing all the partitions made for the
>"hardware" raid windows setup as being separate partitions on the two
>hard disks (identical layout). So I should be able to mirror them using
>sw-raid.

i would not be confident in having md over a fakeraid, sooner or later
the fakeraid will overwrite one of the two md superblocks with the copy
from the other disk, so if you really want to do this, you should use
dmraid instead.

note, there is no bootloader which is yet able to boot from lvm over
dmraid, you will need a separate /stand for the moment.

L.

-- 
Luca Berra -- bluca@comedia.it
        Communication Media & Services S.r.l.
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