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My goal is to install Ubuntu 12.04 LTS using two 1T disks with mixed LVM over RAID. I am running the installation using the mini ISO (bad quality CDs had read error when I tried to use server ISO, so figured out better to rely on the network to give me the software).

The installation program, using the top menu entry Partition disks gives quite nice and intuitive menu based approach to configure RAID and LVM on top of it (using the manual configuration option); I verified that it also saved the changes to the disks and I seem to have the LVM logical volumes created like I wanted as well. However, I do not see how to tell the installation program how I want to use the created LVM groups and RAID device mapper files to house my file systems. When I try to finish the "Partition disks" phase, the installation program complains:

No root file system is defined.

Please correct this from the partitioning menu.


If I go back to the main menu, and try to continue with installing the base system, I am (naturally enough) told to first complete the "Partition disks" phase.

Question: How can I specify my mount points so that the installation can continue? Should and could I do it manually from shell in another virtual console? Specifically is the installation program using the mount points to figure out if the partitioning is finished? And concern is also, when is the /etc/fstab created for the new installed system? (I would prefer strongly to avoid creating yet another installation CD and losing my setup so far.)

FYI: My set-up

  • /boot on a RAID-1 device (/dev/md2);
  • /, /home, /var to be mounted on LVM logical volume in LVM volume group created to incorporate (at the moment) a single RAID-1 device (/dev/md1), and
  • /tmp and another partition in LVM logical volums in another LVM volume group on top of RAID-0 device (/dev/md0).

(My motivation to use LVM is to give some added flexibility in arranging the space in the partitions. This is the first installation using combined LVM/RAID so not sure if this is the most intelligent way of doing this.)

Update I created the file systems by hand on all the devices from shell, mounted them under /target but still the Ubuntu installer did not agree to proceed to installing base system. I have no idea how to convince the installer to assume the step is adequately accomplished.

Then I proceeded to use debootstrap to install the initial system, and continued manually tweaking the system using chroot (repeating the steps that I had already specified during the installation steps and producing a lot of errors during installation of additional packages using apt-get and aptitude due to chroot missing functionality required for configuration of several packages). It was funny that somehow the "Install base system" menu entry kind of started to work (effortlessly fixing the configuration errors) even if it complained about missing partitioning step. I got the rest done using the chroot environment (configuration of grub worked after the "Install base system" menu entry fixed the configuration problems of various packages). Booting to my new system was successful to my great relief.

It seems to me (but have no time and interest to research) that the mini.iso installation program was perhaps buggy. The installation guide clearly says

After you set up MD devices to your liking, you can Finish mdcfg to return back to the partman to create filesystems on your new MD devices and assign them the usual attributes like mountpoints.

And (after preparing the LVM volumes):

After you return to the main partman screen, any created logical volumes will be displayed in the same way as ordinary partitions (and you should treat them as such).

This was true except that there was no way to create file system here. If I am going to ever install 12.04 on a new machine using more complicated storage configurations, and desiring to specify exactly how I want to set-up the configuration I am going to try another CD image (alternative or server image) or just use a live bootable system (CD / USB) and debootstrap without installing too many things into the half-functioning chroot before I have successfully booted into it.

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You need to configure the appropriate volume to be mounted in /. –  psusi Dec 3 '13 at 14:59
Per installation manual for 12.04 it seems it should have been possible. I saw a partitioning menu which told to choose device (including in the list I saw all the LVM / device mapper devices), and the help said that by pressing ENTER would provide appropriate function keys, but the screen just flashed and no keys appeared. Stumblingly I managed to install using debootstrap and chroot. After there was something installed under the /target directory (with lot of errors due to being a dummy chroot), the "Install base system" menu entry started to work. I got a functional system installed. –  FooF Dec 4 '13 at 7:34

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