> -----Original Message-----
> From: Neil Brown [mailto:[EMAIL PROTECTED]]
> Sent: Thursday, June 01, 2000 4:29 AM
> To: Corin Hartland-Swann
> Cc: Theo Van Dinter; [EMAIL PROTECTED]
> Subject: Re: RAID 1+0
>
> On Thursday June 1, [EMAIL PROTECTED] wrote:
> >
> > Theo,
> >
> > On Wed, 31 May 2000, Theo Van Dinter wrote:
> > > On Wed, May 31, 2000 at 09:10:30AM -0400, Andy Poling wrote:
> > > > That's the error you will get any time that you try to
> layer raid levels
> > > > that md does not support layering. It's a safety belt
> mechanism of sorts.
> > >
> > > Arguably, any combination should be allowed, but 0+1 and
> 1+0 at minimum.
> >
> > So, is 0+1 the only combination currently allowed?
>
> Just to set the record straight, no layering of RAID arrays works with
> the 2.2patch set.
>
> 0+1 (meaning a mirrored set of striped sets) appears to work, until a
> drive fails.
> On drive failure, the RAID system attempts to remove one of the
> underlying drives from the overlying mirrored set, fails to find it,
> and dies.
> An instance of this was reported on linux-raid a week ago or so.
> If you want to lookin an archive, the subject line was
> "Disk failure->Error message indicates bug"
So just to confirm, RAID 0+1 is broken, although it appeared to work until
somebody uncovered a bug? I didn't read that thread, or save it (drat!)
> >
> > If so, is anybody working on allowing other combinations?
> >
> > Is anybody else interested in seeing 1+0, 5+0, etc?
>
> 2.4, when if comes out, should be able to support all combinations,
> both raid with raid and raid with lvm. But it doesn't yet (I have a
> patch that I am working on).
Any idea how much hacking time still needs to go into that? I was planning
to rebuild my system with some combination of RAID 1 and 0 fairly soon, I'd
like to know if I should shelf those plans...
Greg
