i wonder what Chris's <Wiz> ESP size is , with circa 60+ OS running on his rig ?
A valid question, Andy
G'day
@rgbellotti
Sunday morning here in Oz and I'm loading up with coffee.
In this Dell rig I have 3 drives operating.
Below are screenshots showing that part of GParted that identifies the ESP (EFI System Partition).
My /dev/sda is the 2 TB internal SATA on the Dell and houses 31 Linux Distros
This is my second-largest ESP and you can see that with 31 Distros it is still using only half the space allocated.
My /dev/sdb is the 256 GB internal Solid State Drive, and it houses 12 Linux Distros
It's the third-largest (read smallest), and 12 Distros are only filling 6.50 MiB.
My /dev/sdc is my 4 TB Western Digital MyBook, mains-powered, USB 3.0 connector.
It houses (today) 25 Distros, today.
This is the largest of my ESP's at 611 MiB, and the 25 Distros account for less than half of that space.
I place my ESPs at the end of each drive, so that if I need to grow the partition, I can do so easily without having them hemmed in by other partitions.
At the second screenshot, from my SSD, the partition above my ESP, /dev/sdb13, was empty at that time, but I have since installed the Arcolinux Cinnamon I am writing from. The partition, size about 20 GiB shows as having 190.56 MiB used, and that is a formatting overhead, under EXT4.
With an ESP being written in FAT32, the overhead is considerably less.
The screenshot below (dark theme on this Distro) shows a sizable chunk of my /dev/sdc external drive.
Here, I have created a dummy ESP of 512 Mib.
My cursor is placed showing the real ESP at /dev/sdc2, and the highlighted dummy one shows the formatting for it taking only 1.02 MiB to set up a partition of this size in FAT2.
So of the 280.09 MiB consumed in /dev/sdc2, less 1.02 MiB we have 279.0 being from the actual 25 Distros.
Why is this relevant?
Not seeking to be argumentative, but friend
@dos2unix has provided 2 links above, with the second being the UEFI spec, a PDF document 2,558 pages long, and no, I ain't going in there, or it will be like Jumanji and I won't be seen for 20 years.
However
200MB is max.
Bigger doesn't hurt anything, but it won't be recognized.
... is not accurate in my experience. One of the Linux Distros, Solus actually requires you to have 512 MiB size to the ESP or it will not install.
https://getsol.us/articles/installation/disks/en/
So the larger sizes I created were with a thought to installing Solus in my environment, but I have not done so.
SUMMARY
Minimum size - 100 MiB (required by some distros)
Maximum size - None that I am aware of but you would never need even 1 GiB
Recommended size if multi-multi-booting - 300 MiB
HTH
Chris Turner
wizardfromoz