make sure exfat fuse and utils are installed on the system

emerge -av sys-fs/exfat-utils sys-fs/fuse-exfat sys-fs/dosfstools


exFAT seems not handle well the switches -pgo that relate to permissions. When using standard switches -avgh, it will trigger errors
rsync: mkstemp “/run/media/3461-3338/ki.txt.ws6eA5” failed: Function not implemented (38)

Instead when coping use the following flags

rsync -rltDv [SRC] [DESTINATION]


Create partitions with parted to look something like

GNU Parted 3.2
Using /dev/sdf
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) print
Model: Multiple Card Reader (scsi)
Disk /dev/sdf: 64.0GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:

Number Start End Size Type File system Flags
1 1049kB 64.0GB 64.0GB primary fat32 lba


Create vfat file system with:

mkfs.vfat -F 32 /dev/sdX1