Software Raid10 on Ubuntu Server - mount file system failed

I have a 1TB RAID10 setup on Ubuntu Server (software, not hardware) and when I setup a small swap space (20GB) and another primary drive it fails to write...

The attempt to mount a file system with type swap in RAID0p5 device # at none failed.

I'm not sure what I should do to get around this error.... here's my setup...

RAID10 device #0 - 1.0 TB Unknown
       #1 primary 980.0GB    F    ext4      /
       #5 logical 20.2 GB    F    swap      swap

Then it lists my 4 hard drives.

From serverfault Webnet

• First, did you run mkswap on the new swap partition?

  Second, have you considered four separate 10.1G swap partitions, one on each drive, rather than a 20.2G partition on a single RAID10 array device? You'll get more swap space, more performance, and the same cost in disk usage.

  Webnet : mkswap? I'm not sure how to run that.... there's no command prompt anywhere.... I hadn't considered that, I guess 10 GB swap on each drive is more efficient...

  Webnet : Wouldn't the installation process run mkswap?

  Slartibartfast : I'm confused. You have Ubuntu Server with no command prompt? Separately, I don't recall if you have to tell the installer that you need to format the swap partition. Running mkswap is easy: mkswap (as root). Finally, /var/log/messages might have errors for your perusal.
  From Slartibartfast