Switch from Mint Petra to Ubuntu 14.04

[The_Clowd_Kraut]

I am almost new to Linux and played with different live CDs. After a while I installed Linux Mint 'Petra' on my PC, but in the end I don't like it and want to use Ubuntu 14.04.

So, I used a USB stick to boot and install it on /sda. Before installation I formatted /sda. It all worked fine, no error messages at all.

Then I restarted and saw in the boot menu:


Ubuntu
Erweiterte Optionen für Ubuntu
Memory test (memtest86+)
Memory test (memtest86+, serial console 115200)
Linux Mint 16 Petra (16) (auf /dev/sdb1)
Erweiterte Optionen für Linux Mint 16 Petra (16) (auf /dev/sdb1)

Okay, some remainings, so I start Ubuntu... and nothing happens. The screen stays black.

When I choose Linux Mint it still starts and works.

What can I do to fix this?

(Singing "I want my U-bun-tu" to the Dire Straits melody of "I want my MTV") :guitar:

[The_Clowd_Kraut]

Second try.

I booted from the USB again, and during installation I formatted sda and sdb, told Ubuntu to use sda mainly.

Result:

Alert! dev/disk/by-uuid/"number of the disk" does not exist.
Dropping to a shell!

And then there is:

(initramfs)

I tried to "mount sda".

Result:
can't read '/etc/fstab': no such file or directory.

Did I kill this PC? #-o

[The_Clowd_Kraut]

Third try. I read about boot-repair and hope to use it to fix this mess. Trying to install it, following the official documentation on this site.

Result:


Failed to fetch http://ppa.launchpad.net/yannubuntu/boot-repair/ubuntu/dists/trusty/main/binary-amd64/Packages 404 Not Found

Some index files failed to download. They have been ignored, or old ones used instead.

Nothing works as it should.

[The_Clowd_Kraut]

Try 4.

Using the grub command line. After finding out which is the other name of the boot disk:


set root=(hd0,msdos1)
linux /vmlinuz root=/dev/sda ro
initrd /initrd.img
boot


Result:


Gave up waiting for root device. ....

ALERT! /dev/sda does not exist.

[fantab]

Post more details about your computer and the hardware inside it, like RAM CPU Graphics No. of HDDs/SSDs etc.
"Try Ubuntu without installing", open Terminal [ctrl+alt+t], post the output of the following;

sudo parted -l
sudo fdisk -l

[The_Clowd_Kraut]

DFI ultra NF4 mainboard
3GB Ram
AMD CPU 64 X2 Dual Core 3800+ x2

Onboard Raid decativated in Bios
IDE Masters and Slaves decativated in Bios (one old IDE is plugged in but will be used later)

4 identical SATA disks:

sda
sdb
sdc
sde

If I choose to do "something different" in the installer I can see that one disk - the first - is shown like this:

/dev/mapper/nvidia_dajcfdae
/dev/mapper/nvidia_dajcfdae1 ext4
/dev/mapper/nvidia_dajcfdae5 swap
/dev/mapper/nvidia_dajcfdae ext4

The others are shown as /dev/sdx etc.

I heard that these mapper or LVM things can cause trouble when setting up Ubuntu on a Raid, but the Raid is switched off, the disks should behave like normal disks.