I have enjoyed installing Ubuntu on my 5 year old iMac and am now at the stage where I want to branch out a little..
I have a backup running, not that it's that important, as I still use an ipad for Banking etc but and here is the question:

My 2017 iMac HD has partitions that still contains the boot system and I wish to delete those (yes there are more than 1) and run Ubuntu 20.4 LTS or whatever the latest version is, on a empty and clean HD.

Rather than saying any more I will ask for help/advice on the best way to do that

You have a link for the apple gear from a computer review site. Or

https://support.apple.com/en-us/HT201634



It will make it easier to suggest something if we knew what hardware exactly we are dealing with.

Good Luck.

I am glad you asked. I had assumed this was a 2017 model but it actually dates back to 2013

iMac (21.5-inch, Late 2013)IMAC 21.5-INCH
16GB 1600MHZ DDR3 SDRAM -2X8GB
1TB FUSION DRIVE
ASSY,PKG,LONG,J16, M89/M19B-K39A
STAND SUPPORT, J16
3.1GHZ CORE I7 QC
3.1GHZ CORE I7 QC/GK107-GX 1GB
NVIDIA GEFORCE GT 750M 1GB GDDR5
MAC OS SW,J16G
KEYBOARD2,USR GDE,DUMMY,J16/J17-AUS
KYBD2,USR GDE,MTG KIT1,J16/J17-AUS
COUNTRY KIT,MTG KIT1,J16-AUS

Ubuntu takes a long time to boot and I can see the disk partitions still being used by apple...
I would like to add a photo of the disks but am not familiar with this site

Greetings, Pi-Piper, and welcome to LQ!

Thank you linustalman.
Ive been busy with a whole range of things all my life and its near impossible to stop so I thought why not upgrade my iMac to Ubuntu, and that's when the trouble started.
I hope to be able to make some progress using this site to get answers to my questions...
You may feel disadvantaged because you don't live in Australia but it could be worse, you could be living in South Africa

Ok. Just making sure your imac was intel based for cpu.

Here is ubuntus documentation
https://help.ubuntu.com/community/Ho...%20USB%20Stick

Shotgun search


Some youtube links

https://www.youtube.com/watch?v=CnoLh2sCK-k
https://www.youtube.com/watch?v=LFgM5es3Aro
https://www.youtube.com/watch?v=EvW4XEMbAn0

Good luck. I always suggest one does a md5sum check on downloaded ubuntu iso to save any headaches later installing a corrupted iso download. Youtube wi;ll show how to do md5sum checks .

Happy Trails,
Rok

Appreciated...
Its not that I have not looked but my searches in the past did not reveal any obvious solutions on how to format the imac HD so the whole thing was available for use.
I shall venture forth and see what sort of confusion I create.

You're come to the right place!

Unfortunately I had already explored those links and not one of them actually talks about formatting the HD which has multiple partitions and then installing Ubuntu.
This macs HD is quite large but I am currently only using a small part of the HD as the rest is used by apple for their partitions. It is those partitions I want to delete.

If you have a distro that works running 'live' on it, use it to install to your drive, it will use the whole disk, if you let it, which is probably the easiest way for a beginner installation.

"LIVE" meaning downloading on line as I install?

I downloaded the app on to a external USB and booted from that following the usually recommended instructions

If me and I aint no mac expert. I would shrink the partition I wanted linux on and leave it blank. Using the mac formatting tools so when I reboot. It boots up when I do my changes.

Then format as ext3 file system during install process on the empty partition and a small swap partition if needed. The linux installer has all the tools to do this on most installers using either cfdisk or gparted. Gparted is the preferred way for begineers.

Then see if os-prober picks up the mac install with

Seems easier to me though since wanting to keep macos on there. To just run a persistent live usb install instead. Google will explain what I said.

Live means a bootable ISO that offers a live version of the operating system with GUI desktop, not just an installer. Usually live is similar to what it'll be like after installation, other than not being installed yet.

Anyways as someone said, the ubuntu installer's default is to use the entire first drive. If you are not offered that choice, you could play around with the "something else" option in the installer and see if you can do what you want. Or alternatively, from that live environment, run gparted and remove all partitions first, then run the installer and hopefully then the default will then be to use whole drive...

Thank you.. It turned out that I had to reinstall the whole system after I tried to format the system using gparted, I upgraded to Ubuntu 21.10 at the same time. I was able to improve the partitions on the 2013 imac but not delete the Mac Boot file. I am happy with the results after going through the whole experience and will leave good enough alone.

Probably the best idea to leave well enough alone. Does it actually show you the grub boot menu? When I did it recently on my old MacPro4,1 converted to 5,1 I had to go through all kinds of foolishness to get it to show the menu. It would boot just not show grub and not just because it had no delay set in the file for it like it will do on install. I think it was a console method I need to change to for it to show, it still takes what seems forever to get to grub as it searches for drives to boot.