Multiboot USB drive
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.
Contents
-
1 Using GRUB and loopback devices
- 1.1 Preparation
- 1.2 Installing GRUB
- 1.3 Configuring GRUB
- 1.4 Boot entries
-
1.5 Boot entries for other distributions
- 1.5.1 Alpine Linux
- 1.5.2 CentOS
- 1.5.3 Clonezilla Live
- 1.5.4 Debian
- 1.5.5 Elementary OS
- 1.5.6 Fedora
- 1.5.7 Gentoo
- 1.5.8 GParted Live
- 1.5.9 Kali Linux
- 1.5.10 Knoppix
- 1.5.11 Linux Mint
- 1.5.12 openSUSE
- 1.5.13 Parabola GNU/Linux-libre
- 1.5.14 Sabayon
- 1.5.15 Slackware Linux
- 1.5.16 SystemRescueCD
- 1.5.17 Slitaz
- 1.5.18 Slax
- 1.5.19 Tails
- 1.5.20 Ubuntu
- 1.5.21 Xubuntu (32 bit)
- 2 Chainloading Windows
- 3 Using Syslinux and memdisk
- 4 See also
Using GRUB and loopback devices
advantages:
- only a single partition required
- all ISO files are found in one directory
- adding and removing ISO files is simple
disadvantages:
- 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
Preparation
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.
Hybrid UEFI GPT + BIOS GPT/MBR boot
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:
- A BIOS boot partition (type EF02)
- An EFI System partition (type EF00 with a FAT32 filesystem)
- 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 PARTITIONS!! 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: https://github.com/aguslr/multibootusb
GLIM (GRUB2 Live ISO Multiboot): https://github.com/thias/glim
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:
/mnt/boot/grub/grub.cfg
# 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:
/mnt/boot/grub/grub.cfg
# 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:
/mnt/boot/grub/grub.cfg
# 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 }
archboot
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
Alpine Linux
menuentry '[loopback]alpine x86_64' { set isofile='/boot/iso/alpine-3.3.3-x86_64.iso' loopback loop $isofile set root=loop linux /boot/vmlinuz-grsec modloop=/boot/modloop-grsec modules=loop,squashfs,sd-mod,usb-storage quiet initrd /boot/initramfs-grsec }
CentOS
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 rd.live.image initrd (loop)/isolinux/initrd0.img }
Clonezilla Live
menuentry "[loopback]clonezilla-live-2.2.3-25-amd64" { set isofile="/boot/iso/clonezilla-live-2.2.3-25-amd64.iso" loopback loop $isofile linux (loop)/live/vmlinuz findiso=$isofile boot=live union=overlay username=user config initrd (loop)/live/initrd.img }
Debian
Live install medium
menuentry '[loopback]debian-live-7.8.0-amd64-xfce-desktop' { set isofile='/boot/iso/debian-live-7.8.0-amd64-xfce-desktop.iso' loopback loop $isofile linux (loop)/live/vmlinuz boot=live config fromiso=/dev/sdb2/$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 }
Fedora
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 rd.live.image quiet initrd (loop)/isolinux/initrd.img }
Gentoo
Desktop LiveDVD
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-0.22.0-2-amd64" { set isofile="/boot/iso/gparted-live-0.22.0-2-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 }
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 }
Knoppix
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 $isofile linux (loop)/boot/isolinux/linux bootfrom=/mnt-iso/$isofile acpi=off keyboard=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 }
openSUSE
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
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 }
Sabayon
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 }
SystemRescueCD
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 }
Slitaz
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 }
Slax
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 }
Tails
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 }
Remove the live-media=removable
option if the iso file is not on removable media.
Ubuntu
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/bootx64.efi.windows }
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.
Preparation
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/
Configuration
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:
boot/syslinux/syslinux.cfg
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