Don’t Uninstall, reformat the partition

Firstly you don’t “uninstall” Ubuntu 16.10 or Kali-Linux, you simply reformat the partition they are sitting in. Most people would probably use NTFS (Windows format) but you can use ext4 for Linux if you like.

NTFS has the advantage as it can be written to and read by both Windows and Linux. ext4 can only be read and written by Linux unless extraordinary steps are taken in Windows with the possibility of data corruption.

You can reformat the partitions in gparted or a number of other programs.

Finding what the partitions are

There are a few ways of discovering the correct partitions to reformat.

Using lsblk to reveal partition device name

If when you installed Ubuntu 16.10 and Kali Linux you gave the partitions a label they would be revealed with the lsblk command:

$ lsblk -o NAME,FSTYPE,LABEL,MOUNTPOINT,SIZE,MODEL
NAME         FSTYPE LABEL            MOUNTPOINT   SIZE MODEL
sr0                                              1024M DVD+/-RW DW316  
sda                                             931.5G HGST HTS721010A9
├─sda4       ntfs   WINRETOOLS                    450M 
├─sda2                                            128M 
├─sda5       ntfs   Image                        11.4G 
├─sda3       ntfs   HGST_Win10       /mnt/d       919G 
└─sda1       vfat   ESP                           500M 
nvme0n1                                           477G Samsung SSD 960 PRO 512GB            
├─nvme0n1p5  ntfs                                 858M 
├─nvme0n1p3                                        16M 
├─nvme0n1p1  ntfs                                 450M 
├─nvme0n1p8  ntfs   Shared_WSL+Linux /mnt/e         9G 
├─nvme0n1p6  ext4   New_Ubuntu_16.04 /           23.7G 
├─nvme0n1p4  ntfs   NVMe_Win10       /mnt/c     363.2G 
├─nvme0n1p10 ext4   Ubuntu_18.04     /mnt/clone  27.2G 
├─nvme0n1p2  vfat                    /boot/efi     99M 
├─nvme0n1p9  swap                    [SWAP]       7.9G 
└─nvme0n1p7  ext4   Old_Ubuntu_16.04 /mnt/old    44.6G 

Imagine I wanted to reformat the partitions Ubuntu 18.04 and Old_Ubuntu_16.04 I would reference them as /dev/nvme0n1p10 and /dev/nvme0n1p7 within gparted or any other partition formatting program. Of course they would likely display the LABEL as well so using lsblk might be unnecessary.

Mount the partition and read /etc/lsb-release

From your terminal (of your currently booted Ubuntu) type:

$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=16.04
DISTRIB_CODENAME=xenial
DISTRIB_DESCRIPTION="Ubuntu 16.04.5 LTS"

We can repeat this command (with minor modification) on every partition after mounting it.

Mount partition

Some people probably find it very easy to mount partitions but I wrote a script for it. I run sudo mount-menu.sh and get this selection screen:

Your Ubuntu 16.10 and Kali partitions will probably be FSTYPE of ext4. They will definitely not be ntfs or vfat. For this example I’ll pick nvme0n1p10 to see what distribution is installed there (yes we can already guess it is Ubuntu 18.04).

Use the Down Arrow key to highlight it and press Enter. The menu will clear and you are left with a message in your terminal:

=====================================================================
Mount Device:  /dev/nvme0n1p10
Mount Name:    /mnt/mount-menu.jcXDv
File System:   ext4
ID:            Ubuntu
RELEASE:       16.04
CODENAME:      xenial
DESCRIPTION:   Ubuntu 16.04.5 LTS
 Size  Used Avail Use%
  27G  9.4G   16G  38%

Mounted partition’s /etc/lsb-release

Now we can repeat the command from the last section with a minor modification:

$ cat /mnt/mount-menu.jcXDv/etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=16.04
DISTRIB_CODENAME=xenial
DISTRIB_DESCRIPTION="Ubuntu 16.04.5 LTS"

Yes I know it looks wrong but I cloned my Ubuntu 16.04 over to the 18.04 partition recently to test Ubuntu’s 16.04 to 18.04 upgrade process (it’s a hobby of mine).

Unmount the partition

The next step is to unmount the partition. I also wrote a script to do that sudo umount-menu.sh:

Highlight the partition you mounted in the last step and press Enter.

The menu will clear and a message will be display:

```

/dev/nvme0n1p10 mounted on /mnt/mount-menu.jcXDv unmounted.

```

You can find both scripts here: Unable to read files between two distros