Here we go again. DOS/MBR vs GPT Partition tables.

[dos2unix]

As a rule, I almost always use GPT partition tables on all my internal drives. I don't of any reason not to.
I know of no disadvantage, and plenty of advnatages. However, I rarely use GPT on my USB thumb drives.
Most of them are formatted with either exFat or fat32.

...however... there are a few exceptions. As much as I would like to rule what everyone on team at work does, it's not the case.
I have read articles on the internet that say things like... You MUST use a GPT partition table to boot into EFI mode, and some other articles which say You MUST use a MBR/DOS partition table to boot into Legacy BIOS.

THESE ARE WRONG!!! I have done the opposite many times. I don't recommend it, and when possible I try to avoid it.
It has caused compatibility issues. Some our servers have GPT disks with legacy /biosboot partitions on them (sysLinux).
and some of our other servers have MBR/DOS disks with /boot/efi partitions on them. Both work fine. Some distro's don't use these partitions, all of our distro's do.

Now having said that, I don't recommend it, and it's possible some BIOS/UEFI's may not support this. We are primarily a Lenovo/Dell shop, with some HPs. I haven't done an actual inventory (I think I could write an ansible script to check this, fairly easily) but best guess, I have less than half a dozen servers in this state. But they work.

All of the servers I have built, in the last.. oh 12 years or so I would say... only have GPT partition tables on them. But I wasn't the person who built some of them.

I have heard some people say their Toshiba/Sony/Acer/Asus laptops don't support this, and that may be true. But it works with my Lenovo and Dell laptops. But just because something works doesn't mean you should do it.

 

[MikeRocor]

When I format a USB stick, I try to make it so that it can boot on both BIOS and UEFI machines so I leave a few empty sectors at the low end (*), use all of the rest except for a few MB at the end for a big main partition then use that last little bit for an EFI partition.

*) I have no real idea how much space grub needs before the first partition but the partitioning never seems to want to start at the first sector anyway, so I just take the default.

The big partition gets formatted as ext4, the EFI partition gets formatted as vfat and I double install grub2 with its files in EFI/BOOT/grub

The double grubbing, of course goes out the window if the drive is over 2 TB (in my case, a USB hard drive instead of a flash stick) because no MBR.

When I partition/format an internal drive, I usually just do it the same way for two reasons: 1) being consistent is nice (and it doesn't cost a noticeable amount of space) and 2) if a computer dies, there's a decent chance that "internal" drive will find its way into another system or end up as an "external USB hard drive"

I'm not a big fan of "many partitions" so I don't see any drawback to using MBR instead of GPT as long as MBR will do the job size-wise. I don't see any drawback to GPT either, except that I know so little about it.