Multiboot USB drive

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Tango-go-next.pngThis article or section is a candidate for moving to Multiboot disk images.Tango-go-next.png

Notes: See discussion (Discuss in Talk:Multiboot USB drive#Scope and title)

A multiboot USB flash drive allows booting multiple ISO files from a single device. The ISO files can be copied to the device and booted directly without unpacking them first. There are multiple methods available, but they may not work for all ISO images.

Using GRUB and loopback devices

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Reason: multiple style issues (Discuss in Talk:Multiboot USB drive#)


  • only a single partition required
  • all ISO files are found in one directory
  • adding and removing ISO files is simple


  • not all ISO images are compatible
  • the original boot menu for the ISO file is not shown
  • it can be difficult to find a working boot entry


Tango-view-fullscreen.pngThis article or section needs expansion.Tango-view-fullscreen.png

Reason: How much extra space is needed for the bootloader? (Discuss in Talk:Multiboot USB drive#)

Create at least one partition and a filesystem supported by GRUB on the USB drive. See Partitioning and File systems#Create a file system. Choose the size based on the total size of the ISO files that you want to store on the drive, and plan for extra space for the bootloader.

Installing GRUB

Simple installation

Mount the filesystem located on the USB drive:

# mount /dev/sdXY /mnt

Create the directory /boot:

# mkdir /mnt/boot

Install GRUB on the USB drive:

# grub-install --target=i386-pc --recheck --boot-directory=/mnt/boot /dev/sdX

In case you want to boot ISOs in UEFI mode, you have to install grub for the UEFI target:

# grub-install --target x86_64-efi --efi-directory /mnt --boot-directory=/mnt/boot --removable

For UEFI, the partition has to be the first one in an MBR partition table and formatted with FAT32.


This configuration is useful for creating an universal USB key, bootable everywhere. First of all you must create a GPT partition table on your device. You need at least 3 partitions:

  1. A BIOS boot partition (type EF02)
  2. An EFI System partition (type EF00 with a FAT32 filesystem)
  3. Your data partition (use a filesystem supported by GRUB)

The BIOS boot partition must be sized 1 MB, while the EFI System partition can be at least as small as 50 MB. The data partition can take up the rest of the space of your drive.

Next you must create a hybrid MBR partition table, as setting the boot flag on the protective MBR partition might not be enough.

Hybrid MBR partition table creation example using gdisk:

# gdisk /dev/sdX

Command (? for help): r
Recovery/transformation command (? for help): h
Type from one to three GPT partition numbers, separated by spaces, to be added to the hybrid MBR, in sequence: 1 2 3
Place EFI GPT (0xEE) partition first in MBR (good for GRUB)? (Y/N): N

Creating entry for GPT partition #1 (MBR partition #2)
Enter an MBR hex code (default EF): 
Set the bootable flag? (Y/N): N

Creating entry for GPT partition #2 (MBR partition #3)
Enter an MBR hex code (default EF): 
Set the bootable flag? (Y/N): N

Creating entry for GPT partition #3 (MBR partition #4)
Enter an MBR hex code (default 83): 
Set the bootable flag? (Y/N): Y

Recovery/transformation command (? for help): x
Expert command (? for help): h
Expert command (? for help): w

Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING

Do you want to proceed? (Y/N): Y

You can now install GRUB to support both EFI + GPT and BIOS + GPT/MBR. The GRUB configuration (--boot-directory) can be kept in the same place.

First, you need to mount the EFI System partition and the data partition of your USB drive. Then, you can install GRUB for EFI with:

# grub-install --target=x86_64-efi --efi-directory=/EFI_MOUNTPOINT --boot-directory=/DATA_MOUNTPOINT/boot --removable --recheck

And for BIOS with:

# grub-install --target=i386-pc --boot-directory=/DATA_MOUNTPOINT/boot --recheck /dev/sdX

As an additional fallback, you can also install GRUB on your MBR-bootable data partition:

# grub-install --target=i386-pc --boot-directory=/DATA_MOUNTPOINT/boot --recheck /dev/sdX3

Configuring GRUB

Using a template

There are some git projects which provide some pre-existing GRUB configuration files, and a nice generic grub.cfg which can be used to load the other boot entries on demand, showing them only if the specified ISO files - or folders containing them - are present on the drive.

Multiboot USB:

GLIM (GRUB2 Live ISO Multiboot):

Manual configuration

For the purpose of multiboot USB drive it is easier to edit grub.cfg by hand instead of generating it. Alternatively, make the following changes in /etc/grub.d/40_custom or /mnt/boot/grub/custom.cfg and generate /mnt/boot/grub/grub.cfg using grub-mkconfig.

As it is recommend to use a persistent name instead of /dev/sdxY to identify the partition on the USB drive where the image files are located, define a variable for convenience to hold the value. If the ISO images are on the same partition as GRUB, use the following to read the UUID at boot time:

# path to the partition holding ISO images (using UUID)
probe -u $root --set=rootuuid
set imgdevpath="/dev/disk/by-uuid/$rootuuid"

Or specify the UUID explicitly:

# path to the partition holding ISO images (using UUID)
set imgdevpath="/dev/disk/by-uuid/UUID_value"

Alternatively, use the device label instead of UUID:

# path to the partition holding ISO images (using labels)
set imgdevpath="/dev/disk/by-label/label_value"

The necessary UUID or label can be found using lsblk -f. Do not use the same label as the Arch ISO for the USB device, otherwise the boot process will fail.

To complete the configuration, a boot entry for each ISO image has to be added below this header, see the next section for examples.

Boot entries

It is assumed that the ISO images are stored in the boot/iso/ directory on the same filesystem where GRUB is installed. Otherwise it would be necessary to prefix the path to ISO file with device identification when using the loopback command, for example loopback loop (hd1,2)$isofile. As this identification of devices is not persistent, it is not used in the examples in this section.

One can use persistent block device naming like so. Replace the UUID according to your ISO filesystem UUID.

# define globally (i.e outside any menuentry)
insmod search_fs_uuid
search --no-floppy --set=isopart --fs-uuid 123-456
# later use inside each menuentry instead
loopback loop ($isopart)$isofile

Arch Linux monthly release

Also see archiso.

menuentry '[loopback]archlinux-2017.04.01-x86_64.iso' {
	set isofile='/boot/iso/archlinux-2017.04.01-x86_64.iso'
	loopback loop $isofile
	linux (loop)/arch/boot/x86_64/vmlinuz archisodevice=/dev/loop0 img_dev=$imgdevpath img_loop=$isofile earlymodules=loop
	initrd (loop)/arch/boot/x86_64/archiso.img
Note: As of archiso v23 (monthly release 2015.10.01), the parameter archisodevice=/dev/loop0 is no longer necessary when boot using GRUB and loopback devices.


Also see archboot.

menuentry '[loopback]archlinux-2014.11-1-archboot' {
	set isofile='/boot/iso/archlinux-2014.11-1-archboot.iso'
	loopback loop $isofile
	linux (loop)/boot/vmlinuz_x86_64 iso_loop_dev=$imgdevpath iso_loop_path=$isofile
	initrd (loop)/boot/initramfs_x86_64.img

Boot entries for other distributions

Tango-edit-cut.pngThis section is being considered for removal.Tango-edit-cut.png

Reason: This is unrelated content to Arch (Discuss in Talk:Multiboot_USB_drive#Scope_and_title)

Alpine Linux

Tip: If you want to boot into a 32-bit system, replace x86_64 with x86.
menuentry '[loopback]alpine x86_64' {
        set isofile='/boot/iso/alpine-extended-3.6.0-x86_64.iso'
        loopback loop $isofile
        set root=loop
        linux /boot/vmlinuz-hardened modloop=/boot/modloop-grsec modules=loop,squashfs,sd-mod,usb-storage quiet
        initrd /boot/initramfs-hardened


Stock installation medium
menuentry "[loopback]CentOS-7.0-1406-x86_64-DVD" {
	set isofile='/boot/iso/CentOS-7.0-1406-x86_64-DVD.iso'
	loopback loop $isofile
	linux (loop)/isolinux/vmlinuz noeject inst.stage2=hd:/dev/sdb2:/$isofile
	initrd (loop)/isolinux/initrd.img
Desktop live medium
menuentry '[loopback]CentOS-7.0-1406-x86_64-GnomeLive' {
	set isofile='/boot/iso/CentOS-7.0-1406-x86_64-GnomeLive.iso'
	loopback loop $isofile
	linux (loop)/isolinux/vmlinuz0 root=live:CDLABEL=CentOS-7-live-GNOME-x86_64 iso-scan/filename=$isofile
	initrd (loop)/isolinux/initrd0.img

Clonezilla Live

Tip: Since 2014.01.05[1], the Arch Linux monthly release contains clonezilla.
menuentry "[loopback]clonezilla-live-20170220-yakkety-amd64" {
	set isofile="/boot/iso/clonezilla-live-20170220-yakkety-amd64.iso"
	loopback loop $isofile
	linux (loop)/live/vmlinuz boot=live union=overlay username=user config components quiet noswap nolocales edd=on nomodeset ocs_live_run=\"ocs-live-general\" ocs_live_extra_param=\"\" keyboard-layouts= ocs_live_batch=\"no\" locales= vga=788 ip=frommedia nosplash toram=filesystem.squashfs findiso=$isofile
	initrd (loop)/live/initrd.img


menuentry '[loopback]debian-live-8.8.0-amd64-gnome-desktop' {
	set isofile='/boot/iso/debian-live-8.8.0-amd64-gnome-desktop.iso'
	loopback loop (hd1,2)$isofile
	linux (loop)/live/vmlinuz boot=live config fromiso=/dev/sdb2$isofile
	initrd (loop)/live/initrd.img

Elementary OS

menuentry '[loopback]elementaryos-freya-amd64.20150411' {
	set isofile='/boot/iso/elementaryos-freya-amd64.20150411.iso'
	loopback loop $isofile
	linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=$isofile locale=en_US.UTF-8
	initrd (loop)/casper/initrd.lz


Stock installation medium
menuentry '[loopback]Fedora-Workstation-netinst-x86_64-24-1.2' {
	set isofile='/boot/iso/Fedora-Workstation-netinst-x86_64-24-1.2.iso'
	loopback loop $isofile
	linux (loop)/isolinux/vmlinuz inst.stage2=hd:LABEL=Fedora-WS-dvd-x86_64-24 iso-scan/filename=$isofile quiet
	initrd (loop)/isolinux/initrd.img
Workstation live medium
menuentry '[loopback]Fedora-Workstation-Live-x86_64-24-1.2' {
	set isofile='/boot/iso/Fedora-Workstation-Live-x86_64-24-1.2.iso'
	loopback loop $isofile
	linux (loop)/isolinux/vmlinuz root=live:CDLABEL=Fedora-WS-Live-24-1-2 iso-scan/filename=$isofile quiet
	initrd (loop)/isolinux/initrd.img


menuentry "[loopback]livedvd-amd64-multilib-20160514" {
	set isofile="/boot/iso/livedvd-amd64-multilib-20160514.iso"
	loopback loop $isofile
	linux (loop)/isolinux/gentoo root=/dev/ram0 init=/linuxrc aufs looptype=squashfs loop=/image.squashfs cdroot isoboot=$isofile vga=791 splash=silent,theme:default console=tty0
	initrd (loop)/isolinux/gentoo.xz 

GParted Live

menuentry "[loopback]gparted-live-0.28.1-1-amd64" {
	set isofile="/boot/iso/gparted-live-0.28.1-1-amd64.iso"
	loopback loop $isofile
	linux (loop)/live/vmlinuz boot=live union=overlay username=user config components quiet noswap noeject toram=filesystem.squashfs ip= nosplash findiso=$isofile
	initrd (loop)/live/initrd.img

Customize your resolution and language to skip the setup questions and boot into X. This uses swap - auto-detected.

menuentry "[loopback]gparted-live-0.28.1-1-amd64 EN_US 1920x1200 SWAP" {
	set isofile="/boot/iso/gparted-live-0.28.1-1-amd64.iso"
	loopback loop $isofile
	linux (loop)/live/vmlinuz boot=live union=overlay username=user config components quiet swapon noeject locales=en_US keyboard-layouts=en xvideomode=1920x1200 gl_batch toram=filesystem.squashfs ip= nosplash findiso=$isofile
	initrd (loop)/live/initrd.img

Kali Linux

menuentry "[loopback]kali-linux-1.0.7-amd64" {
	set isofile='/boot/iso/kali-linux-1.0.7-amd64.iso'
	loopback loop $isofile
	linux (loop)/live/vmlinuz boot=live findiso=$isofile noconfig=sudo username=root hostname=kali
	initrd (loop)/live/initrd.img


menuentry "[loopback]KNOPPIX_V7.4.2DVD-2014-09-28-EN" {
        set isofile="/boot/iso/KNOPPIX_V7.4.2DVD-2014-09-28-EN.iso"
        loopback loop $isofile
        linux (loop)/boot/isolinux/linux bootfrom=/dev/sda2$isofile acpi=off keyboard=us language-us lang=us
        initrd (loop)/boot/isolinux/minirt.gz

Linux Mint

menuentry "Linux Mint 17.2 Cinnamon LTS RC (x64)" {
    set iso=/boot/iso/linuxmint-17.2-cinnamon-64bit.iso
    loopback loop $iso
    linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=$iso noeject noprompt 
    initrd (loop)/casper/initrd.lz


Stock installation medium
menuentry '[loopback]openSUSE-13.1-DVD-x86_64' {
	set isofile='/boot/iso/openSUSE-13.1-DVD-x86_64.iso'
	loopback loop $isofile
	linux (loop)/boot/x86_64/loader/linux install=hd:$isofile
	initrd (loop)/boot/x86_64/loader/initrd
Desktop Live medium
menuentry '[loopback]openSUSE-13.1-KDE-Live-x86_64' {
	set isofile='/boot/iso/openSUSE-13.1-KDE-Live-x86_64.iso'
	loopback loop $isofile
	linux (loop)/boot/x86_64/loader/linux isofrom_device=$imgdevpath isofrom_system=$isofile LANG=en_US.UTF-8
	initrd (loop)/boot/x86_64/loader/initrd

Parabola GNU/Linux-libre

Tip: If you want to boot into a 32-bit system, replace x86_64 with i686.
menuentry '[loopback]parabola-2015.07.01-dual.iso' {
	set isofile='/boot/iso/parabola-2015.07.01-dual.iso'
	loopback loop $isofile
	linux (loop)/parabola/boot/x86_64/vmlinuz parabolaisolabel=PARA_201507 img_dev=$imgdevpath img_loop=$isofile earlymodules=loop
	initrd (loop)/parabola/boot/x86_64/parabolaiso.img
Tip: The label string after parabolaisolabel= needs to be edited when a newer release is used.


menuentry '[loopback]Sabayon_Linux_14.05_amd64_KDE' {
	set isofile='/boot/iso/Sabayon_Linux_14.05_amd64_KDE.iso'
	loopback loop $isofile
	linux (loop)/boot/sabayon root=/dev/ram0 aufs cdroot locale=en_US loop=/livecd.squashfs looptype=squashfs isoboot=$isofile
	initrd (loop)/boot/sabayon.igz

Slackware Linux

menuentry '[loopback]slackware64-14.1-install-dvd' {
	set isofile='/boot/iso/slackware64-14.1-install-dvd.iso'
	loopback loop $isofile
	linux (loop)/kernels/huge.s/bzImage printk.time=0
	initrd (loop)/isolinux/initrd.img


Note: Replace 64 with 32 if you want to boot into a 32-bit system.
menuentry '[loopback]systemrescuecd-x86-4.5.2' {
	set isofile='/boot/iso/systemrescuecd-x86-4.5.2.iso'
	loopback loop $isofile
	linux (loop)/isolinux/rescue64 isoloop=$isofile
	initrd (loop)/isolinux/initram.igz


This image needs to be extracted to the directory given in dir.

menuentry 'slitaz-4.0 core' {
	set dir='/live/slitaz-4.0'
	set root=(hd0,msdos3)
	set lang='pt_BR'
	set kmap='br-abnt2'
	linux ($root)/$dir/bzImage lang=$lang kmap=$kmap rw root=/dev/null vga=normal autologin
	initrd ($root)/$dir/rootfs4.gz ($root)/$dir/rootfs3.gz ($root)/$dir/rootfs2.gz ($root)/$dir/rootfs1.gz


This image needs to be extracted to the directory given in dir.

menuentry 'slax' {
	set dir=/live/slax
	set root=(hd0,msdos3)
	linux $dir/boot/vmlinuz from=$dir vga=normal load_ramdisk=1 prompt_ramdisk=0 printk.time=0 slax.flags=perch,xmode
	initrd $dir/boot/initrfs.img


menuentry "Spinrite" {
	set gfxpayload=text
	set isofile="/boot/iso/spinrite.iso"
	set memdisk="/boot/iso/memdisk4.05"
	linux16 (hd1,gpt3)$memdisk iso
	initrd16 (hd1,gpt3)$isofile


menuentry "[loopback]tails-i386-1.5.iso" {
    set isofile='/boot/iso/tails-i386-1.5.iso'
    loopback loop $isofile
    linux (loop)/live/vmlinuz2 boot=live config findiso=${isofile} live-media=removable apparmor=1 security=apparmor nopersistent noprompt timezone=Etc/UTC block.events_dfl_poll_msecs=1000 noautologin module=Tails
    initrd (loop)/live/initrd2.img
Warning: Emergency memory erasure does not seem to work when booting this way.

Remove the live-media=removable option if the ISO file is not on removable media.


menuentry '[loopback]ubuntu-14.04.1-desktop-amd64' {
	set isofile='/boot/iso/ubuntu-14.04.1-desktop-amd64.iso'
	loopback loop $isofile
	linux (loop)/casper/vmlinuz.efi boot=casper iso-scan/filename=$isofile locale=en_US.UTF-8
	initrd (loop)/casper/initrd.lz

Xubuntu (32 bit)

menuentry '[loopback]Xubuntu-16.04-desktop-i386' {
	set isofile='/boot/iso/xubuntu-16.04-desktop-i386.iso'
	loopback loop $isofile
	linux	(loop)/casper/vmlinuz  file=/cdrom/preseed/xubuntu.seed boot=casper iso-scan/filename=$isofile quiet splash ---
	initrd	(loop)/casper/initrd.lz

Chainloading Windows

It can be very difficult to loopback a Windows install disc. One simple solution that allows you to install a variety of platforms from a USB drive with a single, unified partition is to start with a working, bootable Windows USB drive, and to replace its bootloader with GRUB.

Before installing GRUB, rename or move the Windows bootloader. It should be the default .efi executable - located at (USB)/efi/boot/bootx64.efi for a 64-bit system. Install GRUB in its place, and ensure that it is now the default executable.

You can then chainload the renamed Windows bootloader from GRUB, and also configure GRUB to loopback .iso files as described above.

menuentry '[chain]en_windows_8.1_professional_x64' {
	insmod chain
        chainloader /efi/boot/

Using Syslinux and memdisk

Using the memdisk module, the ISO image is loaded into memory, and its bootloader is loaded. Make sure that the system that will boot this USB drive has sufficient amount of memory for the image file and running operating system.


Make sure that the USB drive is properly partitioned and that there is a partition with file system supported by Syslinux, for example fat32 or ext4. Then install Syslinux to this partition, see Syslinux#Installation[broken link: invalid section].

Install the memdisk module

The memdisk module was not installed during Syslinux installation, it has to be installed manually. Mount the partition where Syslinux is installed to /mnt/ and copy the memdisk module to the same directory where Syslinux is installed:

# cp /usr/lib/syslinux/bios/memdisk /mnt/boot/syslinux/


After copying the ISO files on the USB drive, edit the Syslinux configuration file and create menu entries for the ISO images. The basic entry looks like this:

LABEL some_label
    LINUX memdisk
    INITRD /path/to/image.iso
    APPEND iso

See memdisk on Syslinux wiki for more configuration options.

Caveat for 32-bit systems

When booting a 32-bit system from an image larger than 128MiB, it is necessary to increase the maximum memory usage of vmalloc. This is done by adding vmalloc=valueM to the kernel parameters, where value is larger than the size of the ISO image in MiB.[2]

For example when booting the 32-bit system from the Arch installation ISO, press the Tab key over the Boot Arch Linux (i686) entry and add vmalloc=768M at the end. Skipping this step will result in the following error during boot:

modprobe: ERROR: could not insert 'phram': Input/output error

See also