Bug 25549

Summary: UEFI ESP partitions type, size, filesystem encoding, check
Product: Mageia Reporter: Morgan Leijström <fri>
Component: InstallerAssignee: Mageia tools maintainers <mageiatools>
Status: NEW --- QA Contact:
Severity: enhancement    
Priority: Normal CC: isobuild
Version: Cauldron   
Target Milestone: ---   
Hardware: All   
OS: Linux   
Whiteboard: UEFI, EFI, ESP, Installer, Partitioning
Source RPM: CVE:
Status comment:

Description Morgan Leijström 2019-10-12 14:31:58 CEST 
Small issues to think about:
( From https://bugs.mageia.org/show_bug.cgi?id=25533#c15 )


1) ESP filesystem character encoding
  On my mga7 system the kernel complains:
okt 09 11:44:43 svarten kernel: FAT-fs (sdb1): utf8 is not a recommended IO charset for FAT filesystems, filesystem will be case sensitive!
  Why do our installer choose utf-8 in ESP? A quick web search give that iso8859-1 seem more used but i could be wrong.

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2) ESP may be very small, smaller than FAT32 normally permit
For small ESP, diskdrake should either limit min size (is it 32M for FAT32?) or switch to FAT16 or use FAT32 with smaller cluster size.  What is most compatible?  I did a web search and get anything between 2MB Fat12 and 512MB FAT32 as minimum...  i.e:
https://superuser.com/questions/1310927/what-is-the-absolute-minimum-size-a-uefi-partition-can-be/1310938


Myself settled for 14 MB FAT16 of which is much bigger than needed in my case.
(i had no choice but make it small, see referenced bug) 
Probably some other OS need much more, and some BIOS and bootloaders may not be compatible, but i find no standard...?

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3) somehow after fiddling with size i ended up /boot/EFI not got reformatted. Probably my fault.  But maybe add a check to ask again if it did get resized but not reformatted?
Morgan Leijström 2019-10-12 14:33:56 CEST

Whiteboard: (none) => UEFI, EFI, ESP, Installer, Partitioning

Comment 1 Lewis Smith 2019-10-12 20:47:07 CEST 
> utf8 is not a recommended IO charset for FAT filesystems, filesystem will
> be case sensitive!
Up to a point, yes (I found bizarre examples of case-insensitivity probing my ESP). But so what?

> I did a web search and get ... 512MB FAT32 as minimum
No. For info:
 https://superuser.com/questions/1310927/what-is-the-absolute-minimum-size-a-uefi-partition-can-be/1310938
"FAT32 requires a partition of at least 33,548,800 bytes (32763 KB)"
"... using the FAT32 file system ... recommended minimum size for 4K drives is 260 MB ... emulated sector size is 512 bytes ... minimum partition size for FAT32 drive is ... 32 MB"
Academic; your point is to use FAT<32 for tiny ESPs.

This being an installer issue, assigning to the Mageia tools group, and CC'ing the ISO team. Unsure which is the best.

Assignee: bugsquad => mageiatools
CC: (none) => isobuild