May 23, 2017

Triple boot - looking to reinstall CentOS 7 without affecting order !


good evening everyone!

I have the following set-up:

an i7 with 2 HDDs:

First HDD) a 3 TB HDD dedicated to a licensed Windows 10 pro 64 bits

Second HDD) a 2 TB HDD shared between 2 linux distros: a CentOS 7 KDE and a Linux Mint 18 Cinnamon (both 64 bits)


I bought this PC as bare-bones (without and os).

First, i proceeded to install the Windows 10 64, on the 3TB HDD (on the first HDD). So windows has an entire HDD all to itself.

Then, on the second HDD, the 2 TB one, i proceeded to install, in the following order:
1) CentOS 7 KDE all inclusive (i used a USB stick to boot and install)
and then:
2) Linux Mint 18 Cinnamon with its GRUB2.

So, the Linux Mint 18's GRUB2 controls all booting proccesses and boot order.

On the Linux Mint 18, i also have grub-customizer.

The attached screenshots both show the same thing:
Screenshot 1 --- is the shell with the command df -h
Screenshot 2 -- same thing, except i used the disks utility of Mint 18 Cinnamon

In either screenshot, you will see the following:
- sda: is the 3 TB windows hdd
- sdb: is tne 2 TB hdd which is shared between the linux partitions.

On sdb:
sdb 1, sdb2 and sdb 3 --- all these belong to the CentOS 7 installation
sdb 4, sdb 5 and sdb 6 --- all these belong to the Mint 18 Cinnamon installation (this is the one which also controls the GRUB2)

PROBLEM: seeing as i have an AMD Radeon RX470 4 GBDDR5 graphics board, i tried to install the official drivers in CentOS 7.

This operation went great in Linux Mint 18...but not good at all in CentOS 7!

Now i want to re-install the CentOS 7, but i do not want to mess up the grub2 bootloader (and centos 7 also has grub2!)

if i do a regular re-install it will mess up the GRUb2 by re-writing it!

How precisely do i reinstall CentOS 7, without affecting/re-writing the GRUB2, and without affecting the other OSes boot order?


Click Here!