On the test, when installing Ubuntu Server 14.04 LTS, we will create software RAID1.
I note that when creating RAID will be used mdadm automatically.
I will connect two identical disks to the server (similarly, you can try to create RAID on a virtual machine, for example, created in VirtualBox).
And so, we begin the installation of Ubuntu Server, we get to the disk partitioning stage in which we choose the “manual” partitioning method.
We select the first disk and agree “Create a new empty partition table on this device”, then similarly do the second.
“Software RAID setup” appears at the top, select, we agree to write the changes to the disk that we made above.
Select “Create MD device.”
Next, select the type of device software RAID, in my case RAID1.
We indicate that there are 2 active disks, and 0 backup ones.
We’ll select the active ones, agree to save the changes, and click “Finish”
Next, select “Auto Partition” and “Auto – Use Entire Disk”, select RAID for partitioning.
Next, select “Finish partitioning and write changes to disk”, in the next window we agree to write the changes.
Done, the installation process will continue as usual, but on RAID.
At the end of the installation, the bootloader will be installed on both disks.
I recommend to see my article:
mdadm – utility for managing software RAID arrays
See an example in my video: