Re: Recover array after I panicked

["Patrik Dahlström" <risca@powerlamerz.org>]

On 04/28/2017 01:12 AM, Andreas Klauer wrote:
> On Thu, Apr 27, 2017 at 09:57:20PM +0200, Patrik Dahlström wrote:
> The quick and dirty method is... grow using dd from 5disk raid (overlay)
> to 6disk raid (no overlay) starting from the correct offset (verify!). 
> That resumes your reshape in an offline-ish, hackish manner, and once 
> it's done you have the whole thing. That's the theory anyway.
> 
> Pseudocode:
> 
> mdadm --create /dev/md5 --assume-clean /dev/overlay/{a,b,c}
> mdadm --create /dev/md6 --assume-clean /dev/{a,b,c,d} # +1 drive
I'm stuck at this step
$ mdadm --create --assume-clean /dev/md1 --data-offset=126464K --level=5 --raid-devices=6 /dev/sda /dev/sdb /dev/sdd /dev/sdc /dev/sde /dev/sdf
mdadm: cannot open /dev/sda: Device or resource busy

My overlay setup is keeping /dev/sd[abdce] busy. How do I setup the
overlay to keep it from occupying the disks?
Overlays are currently created like this:
$ dmsetup create ${b} --table "0 $size_bkl snapshot $d $loop P 8"

Best regards
// Patrik