How to make bootable Linux USB with persistent storage that boots on Mac?

Question

I need a working Linux (live) ditro, preferably Debian 9 or CentOS 7, that will show on MacMini (Late 2014) boot menu (holding the option/alt key). Live distro should have persistent storage and work directly from the USB flash drive.

What I tried (unsuccessfully) so far:

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1. Downloaded debian-live-9.4.0-amd64-cinnamon.iso and used Disk Utility to unmount the USB partition, then sudo dd if=./debian-live-9.4.0-amd64-cinnamon.iso of=/dev/rdisk3 bs=1m. USB drive is USB 3.0 Sandisk Extreme 32 GB drive, formatted with OS X Disk Utility in FAT[32] with GUID.
2. When USB drive is plugged in a USB 3.0 hub, then nothing appears on Apple's Startup Manager (when I hold the Option/Alt key). If I plug the USB drive directly to the Mac, then an EFI Boot option appears as expected.
3. With EFI Boot option I successfully booted up to the Debian start menu, but when I select the first option to start the live Debian, then nothing happens. No errors, flash drive never shows activity. It just sits on the Debian start-up image and never goes forward.

Second attempt with CentOS-7-x86_64-LiveGNOME-1708.iso:

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1. Followed the above steps, but this time I added hdiutil convert CentOS-7-x86_64-LiveGNOME-1708.iso -format UDRW -o target.img, then sudo dd if=./target.img.dmg of=/dev/rdisk3 bs=1m

2. Only a Windows option is available on Apple's Startup Manager, but when I select it a black screen appears with no USB drive activity.

3. I also tested Fedora Media Writer, but with the same black screen. CentOS wiki states that:

Exactly the same method (dd for CentOS v6.5) works for CentOS 7. Moreover, the CentOS 7 installer image has a special partitioning which, as of July 2014, most Windows tools do NOT transfer correctly leading to undefined behaviour when booting from the USB key. Applications known (so far) to NOT work are unetbootin, multibootusb and "universal usb installler" - do NOT use these. Confirmed as functioning correctly are Rufus (may depend on options selected, there have been reports of failure with rufus too), Fedora LiveUSB Creator, Win32 Disk Imager, Rawrite32 and dd for Windows.

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I want to reach a working live distro and then add a persistent storage to that image. So, I would like to ask how do I configure Debian 9.4 or CentOS 7.4 live distros, to work with persistent storage on my Mac Mini (Late 2014)? If that is not possible, please suggest a working live Linux distro and exact steps.

Answer 1

It seems that CentOS-7-x86_64-LiveGNOME-1708.iso doesn't support EFI, but only MBR (BIOS) installations as in the pre-6.5 era. This explains why I see only Windows option in Apple's Startup Manager. livecd-iso-to-disk returns the following error: ERROR: This live image does not support EFI booting (see below). "livecd-iso-to-disk" is a command available in CentOS which I run in a Virtual machine.

Then I tested the CentOS 7 Minimal iso which doesn't return any errors in livecd-iso-to-disk command. It shows EFI Boot option on Apple's Startup Manage. But the boot menu has only Install CentOS 7 option (which in turn returns some error that an img file is missing and I should load kernel first).

# livecd-iso-to-disk --format --efi CentOS-7-x86_64-LiveGNOME-1708.iso /dev/sdb1
Verifying image...
/Downloads/CentOS-7-x86_64-LiveGNOME-1708.iso:   dd2ee56a96ea54e734bb44b142bd68b7
Fragment sums: b9473a52d3c9a21298cfbf17a427dc2eec65cb78341dc6c3993fb75b7dc6
Fragment count: 20
Press [Esc] to abort check.
Checking: 100.0%

The media check is complete, the result is: PASS.

It is OK to use this media.
WARNING: THIS WILL DESTROY ANY DATA ON /dev/sdb!!!
Press Enter to continue or ctrl-c to abort

wipefs: WARNING: /dev/sdb: appears to contain 'gpt' partition table
Waiting for devices to settle...
mkdosfs 3.0.9 (31 Jan 2010)
MBR appears to be blank.
Do you want to replace the MBR on this device?
Press Enter to continue or ctrl-c to abort

ERROR: This live image does not support EFI booting
Cleaning up to exit...

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It's interesting that debian-live-9.4.0-amd64-cinnamon.iso returns a similar error
debian-live-9.4.0-amd64-cinnamon.iso uses initrd.img w/o install.img ERROR: This live image does not support EFI booting.
Nevertheless it shows EFI Boot on Apple's Startup Manager, but the live option doesn't go forward (no errors, just Debian background).

# livecd-iso-to-disk --format --efi debian-live-9.4.0-amd64-cinnamon.iso /dev/sdb1
Verifying image...

The media check is complete, the result is: NA.

No checksum information available, unable to verify media.
Are you SURE you want to continue?
Press Enter to continue or ctrl-c to abort

WARNING: THIS WILL DESTROY ANY DATA ON /dev/sdb!!!
Press Enter to continue or ctrl-c to abort

wipefs: WARNING: /dev/sdb: appears to contain 'gpt' partition table
Waiting for devices to settle...
mkdosfs 3.0.9 (31 Jan 2010)
/Downloads/debian-live-9.4.0-amd64-cinnamon.iso uses initrd.img w/o install.img
ERROR: This live image does not support EFI booting
Cleaning up to exit...

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Finally, I used Unetbootin (v6.5.7 for Mac) with ubuntu-16.10-desktop-amd64.iso and then ubuntu-17.10.1-desktop-amd64.iso. Both images started without issues on MacMini (Late 2014). There is an EFI Boot option on Apple's Startup Manager, then I selected the first "Try Ubuntu" option which started Ubuntu live. Unfortunately persistent option of Unetbootin doesn't produce any results (newly created files are deleted on restart).

The USB drive with Ubuntu mounts correctly on Mac OS X and shows numerous files and folders in the Finder. Here is how USB drive looks in diskutil list .
CentOS live iso shows a very different structure with only two folders inside.

At completion Unetbootin shows rather confusing error that The created USB device will not boot off on a Mac. Insert it into a PC, and select the USB boot option in the BIOS boot menu. I ignored this warning (reading some advises on the Internet) and started successfully the Ubuntu image:.
And something unrelated, but Mac OS X 10.13.4 shows a warning that Unetbootin is a 32-bit app.