Re: [PATCH] dm-cache: document zeroing metadata device step

[Austin Chang]

On Sun, Jul 12, 2020 at 08:59:32PM +0100, Matthew Wilcox wrote:
> On Mon, Jul 13, 2020 at 03:40:39AM +0800, Austin Chang wrote:
> > +  # When using dmsetup directly instead of volume manager like lvm2,
> > +  # the first 4k of the metadata device should be zeroed to indicate
> > +  # empty metadata.
> > +  dd if=/dev/zero of=/dev/mapper/metadata bs=4k conv=notrunc
> 
> ... don't you need 'count=1' or you'll zero the entire device?

Oops, I copied the command I just used since zeroing the whole metadata
device didn't harm. But 'count=1' should match what I've just written.
I will send a v2 patch later