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From GitHub:

> It turns out this is surprisingly simple to do: just create a FAT volume with a lot of reserved sectors and put the ext2 into the reserved sectors. This works because the filesystems choose different places to put their superblock: FAT uses the very first sector, while ext2 leaves the first kilobyte unused.

So, is it really two independent file systems? At least when it is read only?

It seems writing to one file system is likely to destroy the other, since they would be unaware of each other's allocated blocks.




> So, is it really two independent file systems?

Yes, they just don't interact with each other.

> It seems writing to one file system is likely to destroy the other, since they would be unaware of each other's allocated blocks.

The entirety of ext2 stays within FAT32's reserved blocks (that is, between the bootsector and the File Allocation Table), so FAT32 won't write over ext2. The inverse is also true, as ext2 knows its formatted size, so it won't write outside of the reserved sectors.


So basically the perfect combination if you want to boot a Raspberry Pi from a single partition for some reason. I like it!


Since the two filesystems are independent, it seems they could have independent content. A filesystem that could boot DOS or Linux.




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