Comment 3 for bug 919281

This is know to affect the Ubuntu Server Daily Build of Ubuntu 12.04, as of March 12, 2012.

The kernel modules for 'dm-mirror' and 'dm-raid' are missing, which prevent the installer's dmraid setup from starting for NVidia and Silicon Image ATA fakeraid controllers.

Compounding this issue, for upgrades of systems that are running lvm2 on top of dmraid mirrors, the lvm2 'vgchange -a y' *does* occur, which then leads the installer to perform the installation on only half of the drives in the raid set.

Curiously, at least on the Silicon Image firmware, this does not break the raid set and start a rebuild, but allows the raid to come up in a very strange, broken manner that rapidly leads to filesystem corruption, and an unusable installation.