https://wiki.archlinux.org/index.php/Multiboot_USB_drive
https://yous.be/2017/11/14/how-to-make-a-bootable-usb-with-grub2-and-iso
https://mbusb.aguslr.com/misc/clonezilla.html
https://github.com/aguslr/multibootusb/tree/master/mbusb.d
aj…

1. naformátovat flashku např. na EXT4
   
2. přimountovat flashku a vytvořit adresáře

   mount /dev/sdXY /mnt
   mkdir /mnt/iso
   mkdir /mnt/boot

3. nakopírovat iso soubory distribucí do /mnt/iso
   
4. nainstalovat GRUB na USB disk

   sudo grub-install --removable --boot-directory=/mnt/boot /dev/sdX

5. nakopírovat memtest

   cp /boot/memtest86+* /mnt/boot

6. vytvořit soubor /mnt/boot/grub/grub.cfg s obsahem např.:

   set timeout=-1
   set default=0
   
   menuentry "Ubuntu Desktop 18.04.1 LTS amd46" {
     set isofile="/iso/ubuntu-18.04.1-desktop-amd64.iso"
     loopback loop $isofile
     linux (loop)/casper/vmlinuz boot=casper file=/preseed/ubuntu.seed iso-scan/filename=$isofile noeject noprompt splash --
     initrd (loop)/casper/initrd.lz
   }
   
   menuentry "Xubuntu 18.04.1 LTS i386" {
     set isofile="/iso/xubuntu-18.04.1-desktop-i386.iso"
     loopback loop $isofile
     linux (loop)/casper/vmlinuz boot=casper file=/preseed/ubuntu.seed iso-scan/filename=$isofile noeject noprompt splash --
     initrd (loop)/casper/initrd.lz
   }
   
   menuentry "Clonezila 2.5.5" {
     set isofile="/iso/clonezilla-live-2.5.5-38-i686-pae.iso"
     loopback loop $isofile
     linux (loop)/live/vmlinuz boot=live components config findiso=$isofile ip=frommedia toram=filesystem.squashfs union=overlay username=user
     initrd (loop)/live/initrd.img
   }
   
   ### BEGIN /etc/grub.d/20_memtest86+ ###
   menuentry 'Memory test (memtest86+)' {
   	insmod part_gpt
   	insmod btrfs
   	set root='hd0,gpt1'
   	if [ x$feature_platform_search_hint = xy ]; then
   	  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt1 --hint-efi=hd0,gpt1 --hint-baremetal=ahci0,gpt1  442D-A863
   	else
   	  search --no-floppy --fs-uuid --set=root 442D-A863
   	fi
   	knetbsd	/boot/memtest86+.elf
   }
   menuentry 'Memory test (memtest86+, serial console 115200)' {
   	insmod part_gpt
   	insmod btrfs
   	set root='hd0,gpt1'
   	if [ x$feature_platform_search_hint = xy ]; then
   	  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt1 --hint-efi=hd0,gpt1 --hint-baremetal=ahci0,gpt1  442D-A863
   	else
   	  search --no-floppy --fs-uuid --set=root 442D-A863
   	fi
   	linux16	/boot/memtest86+.bin console=ttyS0,115200n8
   }
   ### END /etc/grub.d/20_memtest86+ ###

7. !!! V oddíle Memory test změnit všechna čísla 442D-A863 na skutečné UUID disku.

• to zjistíme např:

  lsblk -f