Dmesg: [Mon Mar 31 00:33:29 2025] FAT-fs (sde1): utf8 is not a recommended IO charset for FAT filesystems, filesystem will be case sensitive!

0x6A7232 · March 31, 2025, 4:47am

Did some research, seems CONFIG_FAT_DEFAULT_IOCHARSET should be set to "ascii" (or "iso8859-1" for Latin-1 ou Europe occidentale?

So, CONFIG_FAT_DEFAULT_IOCHARSET=”ascii″ but I don’t know how / where to set that, and it seems to be something that should be updated to default on a new installation as FAT is, by nature, not case-sensitive?

See here for this happening to someone else on a different distro:

https://www.antixforum.com/forums/topic/utf8-is-not-a-recommended-io-charset-for-fat-filesystems/

zeroability · March 31, 2025, 10:19am

Please see the following:

github.com

torvalds/linux/blob/4e82c87058f45e79eeaa4d5bcc3b38dd3dce7209/Documentation/filesystems/vfat.rst

====
VFAT
====

USING VFAT
==========

To use the vfat filesystem, use the filesystem type 'vfat'.  i.e.::

  mount -t vfat /dev/fd0 /mnt


No special partition formatter is required,
'mkdosfs' will work fine if you want to format from within Linux.

VFAT MOUNT OPTIONS
==================

**uid=###**
	Set the owner of all files on this filesystem.

This file has been truncated. show original

You will need to override the setting with the following mount flag:

" iocharset=

Character set to use for converting between the encoding is used for user visible filename and 16 bit Unicode characters. Long filenames are stored on disk in Unicode format, but Unix for the most part doesn’t know how to deal with Unicode. By default, FAT_DEFAULT_IOCHARSET setting is used.

There is also an option of doing UTF-8 translations with the utf8 option."