Problems with a disk from RAID array

[James Wilkinson]

Przemyslaw Gawronski wrote:
> I have a ATA hd, 40GB. On another machine it was running in a hardware
> RAID with a second 40GB disk, giving (on the old machine) 80GB.
> 
> Now I'm was trying to use this hd on a new computer without RAID, just
> as a plain ATA hd. But the FC5 installer would always see it in
> /dev/mapper/ directory as a 80GB hd. And I was wondering what do I have
> to do so it wont be recognized as a RAID member (I guest that's why it's
> in /dev/mapper) but as a regular ATA hd as (/dev/hda).

OK. I'm still not convinced that the old RAID really was hardware, but
that doesn't matter. Evidently Fedora can recognise the remains of the
RAID infrastructure left on the disk.

This procedure:
dd if=/dev/zero of=/dev/hda bs=1024 count=1024
will wipe the first megabyte of /dev/hda. (I suspect you'd need to run
it from a rescue session).

CAUTION: this *will* render *all* partitions on a device inaccessible.
It's basically irreversible.[1]

James.

[1] If you know that this statement ... oversimplifies things, then you
know how difficult it really is to reverse it.
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