Re: Deleting mdadm RAID arrays

On Tuesday February 5, admin@domeny.pl wrote:

% mdadm --zero-superblock /dev/sdb1
mdadm: Couldn't open /dev/sdb1 for write - not zeroing

That's weird.
Why can't it open it?

Maybe you aren't running as root (The '%' prompt is suspicious).
Maybe the kernel has  been told to forget about the partitions of
/dev/sdb.
mdadm will sometimes tell it to do that, but only if you try to
assemble arrays out of whole components.

If that is the problem, then
   blockdev --rereadpt /dev/sdb

will fix it.

NeilBrown