Re: Accessing a RAID disk attached externally via USB

[Frank Wille <frank%phoenix.owl.de@localhost>]

Malcolm Herbert wrote:

>On Tue, Jul 09, 2019 at 08:39:11PM -0400, Greg Troxel wrote:
>|I am assuming that this is raidframe and the original system is NetBSD.

Yes. RAID disk from a NetBSD/sandpoint NAS (Synology DS209J) and my
analyzation system is a NetBSD/macppc iBook G4. So more or less the same
architecture.


>|If you have raid autoconfig enabled, I'd expect the raid set to just
>|appear, similar to how I would expect the original setup worked.
>
>a note of caution on this however - I have had experience with
>a external device and both my internal drive(s) using raidframe
>autoconfigure ... during boot one or other will be remapped to different
>raidN ID ...

Yes. That's what I remembered too. Letting the RAID disk autonconfigure
on a second system might modify it and causes trouble when I try to put
it back into its original place.

So I really want to avoid any write-operation to it. And I made sure that
the kernel on my iBook has no RAID_AUTOCONFIG enabled.


>|The raid header is 64 blocks, so a wedge that is like sd0a but starts
>|64 sectors later and ends in the same place should function like
>|raid0d. Then of course you may have a disklabel or gpt inside the raid.
>
>this seems the safest way ...

Indeed. As Martin already told me in a private mail there is scan_ffs(8)
to find the start sector and size of the partition. Then I had to create
a wedge for it with dkctl(8).

Unfortunately The Sleuth Kit's fls-tool cannot deal with dk(4) devices.
It tells me that it cannot access anything in it, because the size it 0. :(

Seems I have to write an image of that partition somewhere...

-- 
Frank Wille