I currently have the following OS installed and working on multi-boot on my computer : Linux Mint 19.1 Debian 9 Ubuntu 18.04

And I would like to install Cent OS as the fourth OS on my computer. Which parameters should I use for the partitionning ?

My Hard disk has a total size of 1TB and here are the details of my partitions :

Linux Mint : / (sda1) : 761,72GB, ext4

Debian : / (sda6) : 48,18GB, ext4 swap (sda5) : 8074 MB, swap

Ubuntu : /boot/efi (sda7) : 512MB, EFI System Partition / (sda8) : 48,38GB, ext4 Unknown (the one where I'd like to put CentOS) : : 64,83GB, ext4

If I choose "manual partitioning", then I select "Unknown", ext4, then : mount point : / capacity : 64,83GB file system : ext 4 reformat : yes,

then : "Done", I have the following error message :

"[snip EFI yada yada, yada] For a UEFI installation, you must include an EFI System Partition on a GPT-formatted disk, mounted at /boot/efi.

1) Why in God's name do you want to put 4 Linux OS's on a 1TB Drive? Have you lost your mind?!? For less than $60 you could add possibly a 2TB HDD and for about $100 a 1TB SSD.

2) I'm with lissa374. Your Ubuntu install is screwing up your system (ask me how I know). EVERY THING should be set to a Legacy BIOS especially if you are going to have multiple OS's on a single HDD, otherwise you are going to get the type of error message you are receiving.

I am still very Old School and Manually partition my drives using the "Classic" Partitioning scheme. Everything is set for a Legacy BIOS. The ONLY time you need to use UEFI is IF you install Nasty Windows. Me?!? I REFUSE to run Windows! That said unfortunately I provide "Tech Support" for my sister who refuses to become "enlightened" and still uses Windows 7. When on the rare occasions where I am forced to run Windows (Win 95', 2000, 7, 10) I run them as a Virtual Machine). When I am testing an OS it is run first as a Virtual Machine. If I don't like it or if it is not ready for "Prime Time", I nuke it.

Here is a couple ideas you can think about.

1) Ubuntu needs to go and be reinstalled in Legacy BIOS Mode. In most if not all Linux OS's you have a choice to install as either Legacy *or* UEFI mode.

2) For God's sake buy another HDD (2TB > ) or a SSD of at least 1TB. SSD's are to be preferred for routine I/O functions, use a HDD for Storage.

3) After you nuke Ubuntu and reinstalled it, BACKUP THE ENTIRE DISK!!! I do 2 ENTIRE disk BACKUPS for each point release: One Right BEFORE a new point release is due out, and the second right AFTER a new point release comes out and I have configured everything and got everything updated to the way I like it. God forbid something goes south, then I can simply roll back the entire system to the Previous point release. Between those two ENTIRE disk BACKUPS, I use Backupninja to do fully automated Weekly backups of all my Key partitions and major Directories. ALL my BACKUPS are on a SINGLE 2TB HDD (I bought for $60) that is formated as one giant 2TB Partition (/dev/sdb1)

4) IF you plan to make CentOS 7 (and eventually 8... which is maybe a few months away but I will AVOID installing 8.0 like the PLAGUE, and maybe kick the tires in a VM ONLY to see how buggy it is, and may wait Until 8.1 or 8.2 comes out before I actually install the beast. OS's.0 releases are notoriously buggy) your everyday OS of choice, buy at least a 1TB SSD and install it on it. Leave that as being the ONLY OS on the SSD.

5) Go into /etc/grub.d and edit the *40_custom and create entries for your Linux Mint, Debian, and Ubuntu. Use any Text editor of your choice. A good one that is a hold over from the days of DOS is something called Midnight Commander (mc) which is an updated clone of something first created by Norton Utilities called Norton Commander (nc). It is a file browser and more.

6) Download a copy of a program called Grub Customizer, install, and run it. When you next re-boot the machine *all* of your OS's will show on on the one GRUB Menu. Properly configured you can run *any* of the OS's even if they are on different physical drives: /dev/sdb; /dev/sdc; etc. It will also save you if GRUB2 goes south. ... and YES it *DOES* happen. That was why I installed Grub Customizer. Remember the Boy Scout Motto: Be Prepared!

Best Fishes