Sharing how I achieved this setup, may help others and also get some feedback myself.
It will allow to compare well the 2 editions to choose one, then in future can also compare the winner against an entirely different distro.
Orders of installs: Windows 10, Zore Lite, Zore Core.
In picture, the order is: Zorin Core, Win 10, Zorin Lite
In Windows' Disk Management tool, the last 2 partitions are for the 2 Zorin OS-s; they are wrongly labeled Primary, when in fact they are Logical, and within an Extended partition, as the picture of Diskpart utility shows next.
Re-installed my windows 10 (for a different reason than installing linux). Took advantage of this to make all 3 windows partitions (System Reserved, Windows C:, Recovery) be within the first 70GB of the disk.
Inside Windows 10, with . Disk Manag., I created Extended partition for the rest of disk. I think this was optional: I could have just proceeded with installation of Zorin where I could have chosen Logical partitions
Zorin Lite install: the official website procedure but "Something else" - manual partitioning.
The partitioning tool in the installation didn't even show me that I had any Extended partition - it just showed free space.
Inside that free space I created a Logical partition for "/", ext4 Journaling.
Didn't bother with a separate "home" or "swap" partition - I heard of such things, but the default (the automatic, dualboot) Zorin install doesn't bother with these either
Ignored the warning to create EFI/ESP partition: from my little research, on legacy Bios there should be no need for such ESP partition
Tested that the install was OK (worked).
Repeated the same with Zorin Core, in the remaining free space
From what I read, the last OS to have been installed (Z. Core in my case) - that creates the Grub entry and sets that last OS to be first & default in the boot menu.
When I decide that I prefer a different OS than the top one, I'll just need to find way to change the order of OS-s in that boot menu.
Does anyone know how to change that order?
And also how to change the time to wait till the default OS in the list is started?
Or a just good reference that explains it. Thanks.
Can you translate it? The instruction is in German.
You can edit the file ect/default/grub
Change grub default and grub timeout.
Count the number of positions of the operating system in grub menu that should start automatically (start counting with 0) and enter this value in grub default. The default waiting time is 10 seconds (grub timeout=10) and can be changed as required. Don't make it too short so that you can enter grub when there are (boot) problems or you want to boot another kernel.
I had an issue with recent install of Zorin 17.2 with my password. I could not get to a recovery menu item as the default is for GRUB not to show at all. I used GRUB boot repair while booting off the live Ventoy USB stick that held Zorin 17.2 - this automatically then made the default timeout to 10 seconds, which in Zorin is represented by a progressive white line at the top of the screen. If you wish to make the timeout for boot options to be greater, then you need to follow @Forpli 's post.
Can you translate it? The instruction is in German.
Not a problem, the browser translates for me (probably most modern browsers can); thanks.
I just used that method and worked fine.
Don't make it too short so that you can enter grub when there are (boot) problems or you want to boot another kernel.
Thanks for the tip! I read that one might be able to pressshift or esc during boot to force grub menu to show up & stay, but it may not be reliable.
I should have done more searching on this forum - what I asked has already been answered (searching for "dual boot change order" for ex).
It's good to know next and so can also just search all over the web for ubuntu or even linux answers:
For reference, I'll add here some other ways I read about:
Some say that using a fixed line idex (like 0,1..) here is not so reliable as the number and order of menu entries may be overwritten on updates and so could be better to either set the default to the id /title of "menuentry" (which should be found in /boot/grub/grub.cfg ), OR, simpler, to the last user chosen entry, like this:
GRUB_DEFAULT=saved
GRUB_SAVEDEFAULT=true
There's also "grub-customizer" GUI app, but some warn it can mess up grub files/settings.
Finally, there is apparently a way to make another installed Linux OS, other than the last installed, hold the main Grub, and it would make it's entry be at the top at the boot menu. I guess it's important if one plans to delete the last installed Linux OS. https://easylinuxtipsproject.blogspot.com/p/grub.html#ID6
