On Sat, Jun 09, 2018 at 10:36:46PM +0100, Simon Hobson wrote:
> Haines Brown <haines@???> wrote:
>
> > In the partitioning scheme, sda is HD ST1000DX002-2DV1. It has a primary
> > partition that is bootable and the mount point /.

> You probably want to set this partition to unused (or whatever it's
called, it's a looong time since I last did this) so that it doesn't
appear in the mount point table (eventually in fstab of the new
install). I think what you are telling it is that you want sda1 to
mounted as / IN THIS INSTALLATION and that then clashes with your new
/ (on sdc) that you're trying to install to.

In "typical usage:" option when configuring the root partition, there is
no option that would disable it. In any case, I don't want to disable
it, but to be able to boot any disk and use its grub menu to boot it or
any other disk. I've always been able to do that.

It occurs to me that I could simply disconnect the SATA cable from my
sda and then partition sdc and after installation reconnect sda and run
update-grub on the disks. But I hesitate to do it because then the
sda/sdc identity of the disk would change and I might end up unable to
boot either disk. Another approach might be to boot sda run fdisk on
sdc and then do an installation on sdc without partitioning it.

Incidentally, on sdb I have have installed an old Debian (Etch?). When I
try to partition sdc it does not want to use its root partition. only
the root partition of sda. I suspect something has changed between
Jessie and Ascii.

The partitioner in devuan install I suppose is parted, but not sure.

Haines