[CentOS] Kernel panic after removing SW RAID1 partitions, setting up ZFS.

Tue Apr 9 09:10:36 UTC 2019
Tony Mountifield <tony at softins.co.uk>

In article <6566355.ijNRhnPfCt at tesla.schoolpathways.com>,
Benjamin Smith <lists at benjamindsmith.com> wrote:
> System is CentOS 6 all up to date, previously had two drives in MD RAID 
> configuration. 
> md0: sda1/sdb1, 20 GB, OS / Partition
> md1: sda2/sdb2, 1 TB, data mounted as /home 
> Installed kmod ZFS via yum, reboot, zpool works fine. Backed up the /home data 
> 2x, then stopped the sd[ab]2 partition with: 
> mdadm --stop /dev/md1; 
> mdadm --zero-superblock /dev/sd[ab]1; 

Did you mean /dev/sd[ab]2 instead?

> Removed /home in /etc/fstab. Used fdisk to set the partition type to gpt for 
> sda2 and sdb2, then built *then destroyed* a ZFS mirror pool using the two 
> partitions. 
> Now the system won't boot, has a kernel panic. I'm remote, so I'll be going in 
> tomorrow to see what's up. My assumption is that it has something to do with 
> mdadm/RAID not being "fully removed". 
> Any idea what I might have missed? 

I think it's because you clobbered md0 when you did --zero-superblock on sd[ab]1
instead of 2.

Don't you love it when some things count from 0 and others from 1?

Tony Mountifield
Work: tony at softins.co.uk - http://www.softins.co.uk
Play: tony at mountifield.org - http://tony.mountifield.org