The following has been distilled from https://help.ubuntu.com/10.04/serverguide/C/advanced-installation.html and revised to match our operating process.
Follow the installation steps until you get to the Partition disks step, then:
- Select Manual as the partition method.
- Select the first hard drive, and agree to “Create a new empty partition table on this device?”.
- Repeat this step for the second drive.
- Select the “FREE SPACE” on the first drive then select “Create a new partition”.
- Next, select the Size of the partition. This partition will be the swap partition, and a general rule for swap size is twice that of RAM. Enter the partition size, then choose Primary, then Beginning.
- Select the “Use as:” line at the top. By default this is “Ext4 journaling file system”, change that to “physical volume for RAID” then “Done setting up partition”.
- For the / partition once again select “Free Space” on the first drive then “Create a new partition”.
- Use the rest of the free space on the drive and choose Continue, then Primary.
- As with the swap partition, select the “Use as:” line at the top, changing it to “physical volume for RAID”. Also select the “Bootable flag:” line to change the value to “on”. Then choose “Done setting up partition”.
With the partitions setup the arrays are ready to be configured:
- Back in the main “Partition Disks” page, select “Configure Software RAID” at the top.
- Select “yes” to write the changes to disk.
- Choose “Create MD device”.
- Select “RAID1”
- Enter the number of active devices “2”, or the amount of hard drives you have, for the array. Then select “Continue”.
- Next, enter the number of spare devices “0” by default, then choose “Continue”.
- Choose which partitions to use. Generally they will be sda1, sdb1
- For the swap partition choose sda1 and sdb1. Select “Continue” to go to the next step.
- Repeat steps three through seven for the / partition choosing sda2 and sdb2.
- Once done select “Finish”.
There should now be a list of hard drives and RAID devices. The next step is to format and set the mount point for the RAID devices. Treat the RAID device as a local hard drive, format and mount accordingly.
- Select “#1” under the “RAID1 device #0” partition.
- Choose “Use as:”. Then select “swap area”, then “Done setting up partition”.
- Next, select “#1” under the “RAID1 device #1” partition.
- Choose “Use as:”. Then select “Ext4 journaling file system”.
- Then select the “Mount point” and choose “/ – the root file system”. Change any of the other options as appropriate, then select “Done setting up partition”.
- Finally, select “Finish partitioning and write changes to disk”.
- The installer will then ask if you would like to boot in a degraded state, select Yes.