Reinstall broken system keeping data on a RAID1 system

[Rashkae]

On 04/02/2012 12:36 PM, oxy wrote:
> Hi,
>
> I wanna reinstall my ubuntu 12.04. It runs on a RAID1 on
> two identical HDs completely mirrored, including swap.
>
> It was broken after an update with update-manager
> last week. (see thread "login window disapears after sys update").
>
> When i boot the install-CD it recognizes the partitions on the disks
> but doesnt see them as a raid. So if i reconfigure a raid as in the
> first installation and install the system, can i somehow keep the
> home data?
>
Well, you should copy the data anyhow, to be safe against any PEBKAC 
errors in low level operations, such as re-install.

But to answer your question:

You have to install from the the Alt-install CD.  The Ubuntu GUI 
installer still, after all these years, has no support for RAID.

When you reach the parition stage with the text based installer, you 
have to choose "Configure RAID" option to detect and start the existing 
Raid arrays.