Re: How to recreate a dmraid RAID array with mdadm

[GeraldCC <gcsgcatling@bigpond.com>]

On Thursday, November 18, 2010 10:11:49 am Neil Brown wrote:
> On Wed, 17 Nov 2010 17:36:23 -0500
> 
> Mike Viau <viaum@sheridanc.on.ca> wrote:
> > > On Wed, 17 Nov 2010 14:15:14 +1100 <neilb@suse.de> wrote:
> > > 
> > > This looks wrong. mdadm should be looking for the container as listed
> > > in mdadm.conf and it should find a matching uuid on sda and sdb, but
> > > it doesn't.
> > > 
> > > Can you:
> > > 
> > > mdadm -E /dev/sda /dev/sdb ; cat /etc/mdadm/mdadm.conf
> > > 
> > > so I can compare the uuids?
> > 
> > Sure.
> > 
> > # definitions of existing MD arrays ( So you don't have to scroll down :P
> > )
> > 
> > 
> > ARRAY metadata=imsm UUID=084b969a:0808f5b8:6c784fb7:62659383
> > 
> > ARRAY /dev/md/OneTB-RAID1-PV
> > container=084b969a:0808f5b8:6c784fb7:62659383 member=0
> > UUID=ae4a1598:72267ed7:3b34867b:9c56497a
> 
> ....
> 
> >            UUID : 084b969a:0808f5b8:6c784fb7:62659383
> > [OneTB-RAID1-PV]:
> >            UUID : ae4a1598:72267ed7:3b34867b:9c56497a
> 
> ....
> 
> > # definitions of existing MD arrays
> > ARRAY metadata=imsm UUID=084b969a:0808f5b8:6c784fb7:62659383
> > ARRAY /dev/md/OneTB-RAID1-PV
> > container=084b969a:0808f5b8:6c784fb7:62659383 member=0
> > UUID=ae4a1598:72267ed7:3b34867b:9c56497a
> 
> Yes, the uuids are definitely all correct.
> This really should work.  I just tested a similar config and it worked
> exactly as exported.
> Weird.
> 
> Whatever version of mdadm are you running???
> Can you try getting the latest (3.1.4) from
>      http://www.kernel.org/pub/linux/utils/raid/mdadm/
> 
> and see how that works.
> Just
>     make
>     ./mdadm -Asvv
> 
> NeilBrown
Hi,
I am just starting to use RAID on my systems and it was suggested that I make 
sure my drives were set to raid by:---- "fdisk -l"
This should say that the relavent drives are set to "raid auto-detect".
Gerald