[CentOS] DegradedArray message

[David McGuffey]

On Mon, 2014-12-08 at 21:11 -0500, David McGuffey wrote:
> On Thu, 2014-12-04 at 16:46 -0800, Gordon Messmer wrote:
> > On 12/04/2014 05:45 AM, David McGuffey wrote:
> 
> > In practice, however, there's a bunch of information you didn't provide, 
> > so some of those steps are wrong.
> > 
> > I'm not sure what dm-0, dm-2 and dm-3 are, but they're indicated in your 
> > mdstat.  I'm guessing that you made partitions, and then made LVM or 
> > crypto devices, and then did RAID on top of that.  If either of those 
> > are correct, that's completely the wrong way to build RAID sets.  You 
> > risk either bad performance from doing crypto more often than is 
> > required, or possibly corruption as a result of LVM not mapping blocks 
> > the way you expect.
> > 
> > If you build software RAID, I really strongly recommend that you keep it 
> > as simple as possible.  That means a) build sofware RAID sets from raw 
> > partitions and b) use as few partitions as possible.
> > 
> 
> Gordon,
> 
> Agree, I've probably made it too complicated. It is a workstation with
> sensitive data on it so I've encrypted the partitions.
> 
> md1 is fairly simple...two large disks in raid1, encrypted, and mounted
> as /home.
> 
> md0 is probably way too complicated and not a good way to go.  The
> sensitive data in md0 is in /var (virtual machines).
> 
> I've backed up both /home and /var/lib/libvirt/images, so I think I'll
> start over on md0 with a new disk and a fresh install.
> 
> Dave
> 
Armed with a backup I decided to use the disk utility GUI to check the
array and then re-attach the disk. After a rebuild phase it reattached
and the state changed to 'clean.' I rebooted to see if it would stay
attached; it did.

I'll still get ready for another failure. Will read up on the best
methods to have an encrypted filesystem on top of raid-1.

Dave M