What's the proper way of enabling persistence on Fedora Workstation?

[Hash6232]

I used persistence_ext4_4GB_vtoycow.dat from the latest backend image files and renamed it to fedora.dat. I am booting from UEFI and the ISO boots correctly with the kernel parameters specified in the custom grub.cfg file when persistence is disabled. But when it's enabled I am greeted by an error message prompting me to go in emergency mode making me enter a shell. Right before the error message, the console displays a message saying it could not mount the selinuxfs partition

I just tried using an XFS dat file but same error. I'll attach it as a new comment

{
    "control":[
        { "VTOY_DEFAULT_SEARCH_ROOT": "/ventoy/iso" }
    ],
    "persistence":[
        {
            "image": "/ventoy/iso/Fedora-Workstation-Live-x86_64-******.iso",
            "backend":[
                "/ventoy/persistence/fedora.dat"
            ]
        }
    ],
    "conf_replace_uefi":[
        {
            "iso": "/ventoy/iso/Fedora-Workstation-Live-x86_64-******.iso",
            "org": "/EFI/BOOT/grub.cfg",
            "new": "/ventoy/boot/fedora/grub.cfg"
        }
    ]
}

Directory tree

D:\VENTOY
│   ventoy.json
│   ventoy_backup.json
│
├───iso
│       dban-2.3.0_i586.iso
│       shredos-2024.11_27_x86-64_0.38_20250125_vanilla.iso
│       gparted-live-1.7.0-1-amd64.iso
│       netboot.xyz.iso
│       Fedora-Workstation-Live-x86_64-41-1.4.iso
│
├───persistence
│       fedora.dat
│
└───boot
    └───fedora
            grub.cfg

[Hash6232]

This is a dump of the custom grub.cfg file in case it's needed. It's based on the grub file found inside the Fedora iso file at Fedora-Workstation-Live-x86_64-41-1.4.iso\EFI\BOOT\grub.cfg

set default="1"

function load_video {
  insmod efi_gop
  insmod efi_uga
  insmod video_bochs
  insmod video_cirrus
  insmod all_video
}

load_video
set gfxpayload=keep
insmod gzio
insmod part_gpt
insmod ext2

set timeout=60
### END /etc/grub.d/00_header ###

search --no-floppy --set=root -l 'Fedora-WS-Live-41-1-4'

### BEGIN /etc/grub.d/10_linux ###
menuentry 'Start Fedora-Workstation-Live 41' --class fedora --class gnu-linux --class gnu --class os {
	linuxefi /images/pxeboot/vmlinuz root=live:CDLABEL=Fedora-WS-Live-41-1-4  rd.live.image quiet rhgb selinux=0 i915.enable_psr=0
	initrdefi /images/pxeboot/initrd.img
}
menuentry 'Test this media & start Fedora-Workstation-Live 41' --class fedora --class gnu-linux --class gnu --class os {
	linuxefi /images/pxeboot/vmlinuz root=live:CDLABEL=Fedora-WS-Live-41-1-4  rd.live.image rd.live.check quiet selinux=0 i915.enable_psr=0
	initrdefi /images/pxeboot/initrd.img
}
submenu 'Troubleshooting -->' {
	menuentry 'Start Fedora-Workstation-Live 41 in basic graphics mode' --class fedora --class gnu-linux --class gnu --class os {
		linuxefi /images/pxeboot/vmlinuz root=live:CDLABEL=Fedora-WS-Live-41-1-4  rd.live.image nomodeset quiet rhgb selinux=0 i915.enable_psr=0
		initrdefi /images/pxeboot/initrd.img
	}
}

[Hash6232]

[Hash6232]

[Hash6232]

Possibly an incompatibility with EXFAT? My USB partition where the iso and configs are stored is formatted as exFAT

[steve6375]

https://www.kalitsune.net/blog/persistent-fedora-install-on-ventoy

[Hash6232]

Using VFAT would prevent me from using persistence file larger than 4GB. I also tried looking for some info and in this documentation different file systems are mentioned so I assume latest fedora does support overlay in different formats than VFAT https://docs.fedoraproject.org/en-US/quick-docs/creating-and-using-a-live-installation-image/#using-the-livecd-iso-to-disk-tool

I also tried baking the persistence file myself using the bash script provided on the ventoy website but again same error. I also noticed that ventoy created an overlay directory in the root of the USB drive which is empty. Could it be that fedora or ventoy are looking for the overlay file in there instead?

EXFAT is also the default file system used by ventoy https://www.ventoy.net/en/doc_disk_layout_gpt.html

[steve6375]

I edited my response- did you see the URL?

[Hash6232]

I did but it's pretty much the same procedure I followed. The only difference is that a BIOS grub is added but I am booting in UEFI mode and I double checked that the kernel parameters are there when the grub menu appears. I also reformatted and reinstalled the usb drive for good measure and used EXFAT again since it's the default filesystem used by the ventoy installer. I also tried booting from Fedora 42 beta and the same error appears.

I'll try downloading the same fedora version used in the guide you just linked while I try booting from different computers to see what happens

[Hash6232]

Nope. Same error with Fedora 39