On 20/05/18 12:10, Andrew Greig wrote:
> Since I am installing Ubuntu 18.04 LTS I have no mdadm to use in the
> install process,

Yes, you would have to use the "server" image to have mdadm available at
install time.  But since you're not installing the base system to the
RAID drives, that doesn't matter.  You can install mdadm after the
install is finished.

> so I have pulled the leads on the 2 x 2Tb drives

No real benefit to that, but if it makes things easier for you, sure.

> will install Ubuntu using LVM and their default setup for that disk
> and when I have a running system I can plug in the two drives and run
> mdadm to set up the raid formatting the disks as part of the
> process?

Yes.  Set up mdadm first, then LVM on top of the newly created RAID
volume.  Of course you can also use LVM on your 1TB disk as well - if
you set that up during the initial install, that's fine.  I usually use
the command line tools, but I believe the graphical disk management
tools can handle RAID and LVM these days.

Hope that helps,
                Andrew