ISOs Explained + four programs to make Linux boot media
Linux boot media need not be tricky! In today's episode, I'll talk about four ways to flash an ISO from Windows (and other systems too). I know a lot of you are switching to Linux because of Micros...
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I curious because I don't have the skill to test it myself but can you just manually copy everything to USB it's just work?
No, the drive needs a boot partition for the bios to know there is something to be booted on the drive.
Most Linux ISO's do properly include the partitions in the ISO, so you can clone the iso to a drive and that should work, using dd for example. But just copying the files won't work.
iirc windows iso's did use to support just creating a fat32 partition and moving all the files over, not sure how they managed that. But now the international ISO for win 11 has a file that's more than the max 4Gb allowed by fat32, so you can't do that anymore either.
No idea if this exists for Linux, but there's a program for Windows called GuiFormat that allows formatting of larger thumb drives to be fat32.
That's not the only issue, fat32 also has a hard limit on single file size. The largest a single file can be is 4GiB, and afaik you just can't get around that with fat.
iirc, the way windows deals with this in its media creation tool is that it strips out locales and other things you don't need, based on the options you selected previously, so the file ends up being small enough to fit.
Dunno how GuiFormat gets around those limitations (something to do with block sizes, I think), but I've never had any trouble with it.
There's better options than fat32, anyway, just pointing out that the 4GB limit has a workaround, and YMMV.
In the general case, no, but there are some rare specific cases where that does work.
If you're trying to produce Linux media that will boot on a single-board computer that has an onboard bootloader, like a Pi 4, you can indeed just partition the target medium and copy the files manually (been there, done that, working with a custom Gentoo install with no ISO).
If the bootloader has to be on the target medium (as it would for a desktop or laptop), then that won't work unless you also do a manual bootloader install after copying everything. Not impossible, but at that point you're hitting the level of complexity where it's easier to figure out the correct dd command.
(As for Windows? Don't even bother. It hates being worked on with anything but its own tools.)
