So I just got done hopping OSes left right and center unplugging and plugging back in a USB stick like crazy and I finally got to this point.
Is there any way I can make it so that there’s 4 primary partitions and a single extended partition?
I just found out that I did all of this testing on Windows 10, so it doesn’t even matter because it doesn’t work for Windows 7 or 8.1.
Abandon thread. -.-
MBR partitioning scheme (master boot record) needs to fit both a small bootloader and a partition table into 512bytes. There’s only space in the spec for 4 entries ie. 4 primary partitions, which takes up about a third of that space.
You could make one of them an “extended” partition, which is just a nested structure, first sector of this “extended” partition will be another MBR.
Boot process on legacy PCs was to read this 512 bytes into a ram location and jump to it… dead easy to implement in firmware. No need to understand filesystems, OSes, partition tables, very simple.
With UEFI/EFI, the firmware can actually read partition tables and filesystems when booting. It expects to see a partition table in GPT format (can have more than 4 partitions), and will go looking for a partition with type EF02 that’s also marked active/bootable, it’ll expect to see a fat32 formatted filesystem, and it’ll load potentially very large files from that partition… all that before actually executing any code stored on the partition.
Use GPT (unless you have pre sandy bridge hardware or need to use DOS or some other ancient software).