ISOs in Ventoy partition not visible

[Steve2926]

I dont think the FAT16 partition is 16GB as the maximum size for FAT16 is 2GB or possible 4GB.
https://en.wikipedia.org/wiki/Design_of_...ize_limits

My guess is that you have a fake USB flash drive. Can you reproduce the issue on a different make of flash drive (preferably a good make like SanDisk)?
Also, after copying on the ISO file, make sure to sync and eject the USB drive before rebooting or unplugging the USB drive.
Then check again that the ISO file is still on the USB drive under Linux again.

[garta34]

I just discovered that I misspoke above: my Ventoy stick is currently formatted FAT32 and the various ISO-files on the stick are recognized by multiple computers. However, I had originally formatted it exFAT and discovered that all computers I tried the stick on did /not/ recognize that there were any ISO-files on the stick, regardless of the size of the individual ISO-files.

So, my question should be: do computer BIOSes not natively recognize exFAT and I somehow need to "activate" an exFAT driver on the USB stick?

[Steve2926]

Legacy BIOSes do not recognise any filesystem. In the case of Ventoy, it boots to grub2. Grub2 contains filesystem drivers which are loaded as modules. The grub2 used by Ventoy understands many filesystems including exFAT, FAT, NTFS and ext2/3/4 and more.
So you have a USB drive that appears to work as FAT32 and not as exFAT.
Since no one else (millions of people) has this issue, maybe your USB drive is a fake or it is faulty?
What size is the working FAT32 partition? What size is the non-working exFAT partition?

[garta34]

I guess it is always a possibility that the USB drive is faulty but when I do a file compare of the more than 10 ISOs I have copied to it with the original ISOs on my computer they are identical. I therefore deem it unlikely that the USB drive is faulty.

The working Ventoy FAT32 partition is 31GB and the exFAT was the exact same size. When I had it formatted as exFAT I could see the various ISOs when I mounted it on a running CentOS system, I just could not see any ISOs when I booted it on any of the four computers I tried it on. Plugging the USB stick back into my running CentOS system they were visible and a file compare was good. Now when I have it formatted as FAT32 I can view and boot the ISOs as expected.

So, I am back at my original question: Do I need to make sure the exFAT driver is active in Ventoy somehow? How can I make sure it can be loaded? Maybe there is something wrong with the configuration of Ventoy on my stick when I installed it?

I think I found some old posts about problems booting from exFAT on the forum.