Multi-distro LiveUSB

1 Introduction

This howto shows how to create a liveusb that can:

• contain more than one iso.
• contain other partitions

2 Howto

This howto was tested on qemu, adapt it for real hardware.

• convert The isos to be able to run on a partition

# isohybrid --partok trisquel_6.0.1_i686.iso

parabola-2013.09.01-dual.iso seems to be already converted.

• create the image, I used qemu for testing so I created a loop file.

# qemu-img create -f raw ./usd.img 3780M

• find the isos size with size.sh

# ./size.sh trisquel_6.0.1_i686.iso
+708608K

• create partitions with fdisk, for example:

# fdisk ./usd.img

Welcome to fdisk (util-linux 2.25).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0xb94f94ec.

Command (m for help): n
Partition type
   p   primary (0 primary, 0 extended, 4 free)
   e   extended (container for logical partitions)
Select (default p): p
Partition number (1-4, default 1): 
First sector (2048-7741439, default 2048): 
Last sector, +sectors or +size{K,M,G,T,P} (2048-7741439, default 7741439): +32M

Created a new partition 1 of type 'Linux' and of size 32 MiB.

Command (m for help): p
Disk ./usd.img: 3.7 GiB, 3963617280 bytes, 7741440 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xb94f94ec

Device     Boot Start   End Sectors Size Id Type
./usd.img1       2048 67583   65536  32M 83 Linux

Command (m for help): n
Partition type
   p   primary (1 primary, 0 extended, 3 free)
   e   extended (container for logical partitions)
Select (default p): 

Using default response p.
Partition number (2-4, default 2): 
First sector (67584-7741439, default 67584): 
Last sector, +sectors or +size{K,M,G,T,P} (67584-7741439, default 7741439): +708608K

Created a new partition 2 of type 'Linux' and of size 692 MiB.

Command (m for help): p
Disk ./usd.img: 3.7 GiB, 3963617280 bytes, 7741440 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xb94f94ec

Device     Boot Start     End Sectors  Size Id Type
./usd.img1       2048   67583   65536   32M 83 Linux
./usd.img2      67584 1484799 1417216  692M 83 Linux

Command (m for help): n
Partition type
   p   primary (2 primary, 0 extended, 2 free)
   e   extended (container for logical partitions)
Select (default p): p
Partition number (3,4, default 3): 
First sector (1484800-7741439, default 1484800): 
Last sector, +sectors or +size{K,M,G,T,P} (1484800-7741439, default 7741439): +481280K

Created a new partition 3 of type 'Linux' and of size 470 MiB.

Command (m for help): p
Disk ./usd.img: 3.7 GiB, 3963617280 bytes, 7741440 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xb94f94ec

Device     Boot   Start     End Sectors  Size Id Type
./usd.img1         2048   67583   65536   32M 83 Linux
./usd.img2        67584 1484799 1417216  692M 83 Linux
./usd.img3      1484800 2447359  962560  470M 83 Linux

Command (m for help): n
Partition type
   p   primary (3 primary, 0 extended, 1 free)
   e   extended (container for logical partitions)
Select (default e): p

Selected partition 4
First sector (2447360-7741439, default 2447360): 
Last sector, +sectors or +size{K,M,G,T,P} (2447360-7741439, default 7741439): 

Created a new partition 4 of type 'Linux' and of size 2.5 GiB.

Command (m for help): 


Command (m for help): p

Disk ./usd.img: 3.7 GiB, 3963617280 bytes, 7741440 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xb94f94ec

Device     Boot   Start     End Sectors  Size Id Type
./usd.img1         2048   67583   65536   32M 83 Linux
./usd.img2        67584 1484799 1417216  692M 83 Linux
./usd.img3      1484800 2447359  962560  470M 83 Linux
./usd.img4      2447360 7741439 5294080  2.5G 83 Linux

Command (m for help): w
The partition table has been altered.
Syncing disks.

• check if there is already some dm-mapper loop partitions

# ls -l /dev/mapper/loop*
ls: cannot access /dev/mapper/loop*: No such file or directory

If there is none, you're good

• Then add the partitions mapping

kpartx -a usd.img

• check if it worked:

ls -l /dev/mapper/loop*

# ls -l /dev/mapper/loop*
lrwxrwxrwx 1 root root 7 Sep  7 12:54 /dev/mapper/loop0p1 -> ../dm-7
lrwxrwxrwx 1 root root 7 Sep  7 12:54 /dev/mapper/loop0p2 -> ../dm-8
lrwxrwxrwx 1 root root 7 Sep  7 12:54 /dev/mapper/loop0p3 -> ../dm-9
lrwxrwxrwx 1 root root 8 Sep  7 12:54 /dev/mapper/loop0p4 -> ../dm-10

• install grub on the boot partition:

# mkfs.ext4 /dev/mapper/loop0p1 
mount /dev/mapper/loop0p1 /mnt
cp -a /boot/grub/ /mnt/
umount /mnt 
mount /dev/mapper/loop0p1 /boot
grub-install ./usd.img
umount /boot

• Add the isos:

ddrescue trisquel_6.0.1_i686.iso /dev/mapper/loop0p2 -f
ddrescue parabola-2013.09.01-dual.iso /dev/mapper/loop0p3 -f

• Add the data partition:

mkfs.ext4 /dev/mapper/loop0p4 

# kpartx -d ./usd.img
# dmsetup remove /dev/mapper/loop0p4
# dmsetup remove /dev/mapper/loop0p3
# dmsetup remove /dev/mapper/loop0p2
# dmsetup remove /dev/mapper/loop0p1
# sync

Now you have the image ready, I tested with qemu like that:

qemu-system-i386 -enable-kvm -serial stdio -m 2047M -hda ./usd.img

Then in grub I did:

set root=hd0,msdos2
syslinux_configfile /isolinux/isolinux.cfg

And the trisquel menu appeared. I then could boot trisquel

3 grub.cfg

menuentry 'Trisquel' {
        set root=hd0,msdos2
        syslinux_configfile /isolinux/isolinux.cfg
}

menuentry 'Parabola' {

}