From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Bryn M. Reeves" <bmr@redhat.com>
Subject: Re: Choosing the device name in kpartx.
Date: Mon, 3 Oct 2016 12:48:31 +0100
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On Mon, Oct 03, 2016 at 07:59:41AM +0100, Bryn M. Reeves wrote:
> On Sun, Oct 02, 2016 at 02:10:50AM -0300, Andre Caldas wrote:
> > As I understood it, when I call
> > $ kpartx -a disk.img
> > kpartx chooses a "device name" X, detects the partitions and their
> > numbers N, and creates device nodes with naming
> > XpN.
> 
> This command performs several steps for you. You can have greater
> control by issuing those steps yourself:
> 
> 1. Create a loop device mapping the image (/dev/loopN)
> 2. Create a device-mapper device with a linear map of the loop:
> 
>    # dmsetup create $DEV_NAME --table="0 $DEV_SIZE linear /dev/loopN"

Typo: this should be "0 $DEV_SIZE linear /dev/loopN 0" (an extra '0'
at the end) - this is the starting offset for the mapping, which is
always zero for a whole-disk device.

Regards,
Bryn.