Re: about debian installation on gpt and mbr hard drive

[deloptes <deloptes@gmail.com>]

Hi,
I just did my first UEFI few weeks ago. I had it on the list for coupel of
years already, but only recently had the time to do it.
Here I share my notes and experience briefly.

kaye n wrote:

> Hello Friends!
> 

I don't know you, so friend in my language is a bit too much, but good
fellow is OK :)

> Can someone please confirm to me once and for all if I'm correct with
> these assumptions regarding debian installation on hard drives:
> 
> 1.  If the hdd has an MBR partition style, that hdd needs to have a FAT32
> partition, flagged as esp and with mount point at /boot/efi.  If this is
> correct, can I put it anywhere on the hdd or must it be on the left-most
> part of the drive (when looking at it in GParted) ?  Also how big should
> the FAT32 partition be if, a) no Windows would be installed on the hdd,
> and b) Windows will be installed on the hdd making it a dual boot system.
> 

No you do not need FAT32 if using dos type partition or what you call MBR,
though I am not sure if correct, because MBR is also written when using
GPT.
Note that when you format GPT the old partition table (MBR) is deleted - so
your disk is gone.

I guess for convenience it is better to do it on the first partition
(beginning of the disk), cause who knows how the UEFI was implemented. In
theory AFAIK it shouldn't matter, but ... better be on the safe side.

Regarding size etc. look below - I haven't played with the various options.

> 2.  If the hdd has a GPT partition style, there is no need for a FAT32
> partition (that is flagged as esp and mounted at /boot/efi), unless of
> course you would install Windows 10, making it a dual boot system, but
> even then, Debian would not use or need the FAT32 partition.
> 

You need to mount it under /boot/efi when you do updates/upgrades. Grub is
writing there.

Here the notes for a USB stick, so that I can use this stick for converting
other PCs to UEFI. I used debootstrap

        Model: Kingston DataTraveler 2.0 (scsi)
        Disk /dev/sdb: 60647488s
        Sector size (logical/physical): 512B/512B
        Partition Table: gpt
        Disk Flags:
        
        Number  Start      End        Size       File system     Name  Flags
        1      2048s      1001471s   999424s    fat32           EFI   boot, esp
        2      1001472s   2050047s   1048576s   ext4
        3      2050048s   10438655s  8388608s   linux-swap(v1)
        4      10438656s  60647454s  50208799s  ext4

Mount partitions

        /dev/sdb1 /mnt/target/boot/efi
        /dev/sdb2 /mnt/target/boot/
        /dev/sdb4 /mnt/target/

Chroot then install grub and do update-grub this should be done from efi
booted system. To produce this USB stick I had to boot in UEFI from the
debian CD in rescue mode.

Size is 488MB, but is mostly empty, so even the half would work, but with
450-500 you are on the safe side.

Hope it helps
regards