To prepare the USB stick, you will need a system where GNU/Linux is
already running and where USB is supported. With current GNU/Linux systems
the USB stick should be automatically recognized when you insert it. If
it is not you should check that the usb-storage kernel module is loaded.
When the USB stick is inserted, it will be mapped to a device named
/dev/sdX, where the “X” is a letter
in the range a-z. You should be able to see to which device the USB
stick was mapped by running the command dmesg after
inserting it. To write to your stick, you may have to turn off its write
The procedures described in this section will destroy anything already on the device! Make very sure that you use the correct device name for your USB stick. If you use the wrong device the result could be that all information on for example a hard disk could be lost.
Debian installation images can now be written directly to a USB stick, which is a very easy way to make a bootable USB stick. Simply choose an image (such as the netinst, CD, DVD-1, or netboot) that will fit on your USB stick. See Section 4.1, “Official Debian GNU/Linux installation images” to get an installation image.
for very small USB sticks, only a few megabytes in size, you can download
mini.iso image from the
directory (at the location mentioned in Section 4.2.1, “Where to Find Installation Images”).
The installation image you choose should be written directly to the USB stick, overwriting its current contents. For example, when using an existing GNU/Linux system, the image file can be written to a USB stick as follows, after having made sure that the stick is unmounted:
Information about how to do this on other operating systems can be found in the Debian CD FAQ.
The image must be written to the whole-disk device and not a partition, e.g. /dev/sdb and not /dev/sdb1. Do not use tools like unetbootin which alter the image.
Simply writing the installation image to USB like this should work fine for most users. The other options below are more complex, mainly for people with specialised needs.
The hybrid image on the stick does not occupy all the storage space, so it may be worth considering using the free space to hold firmware files or packages or any other files of your choice. This could be useful if you have only one stick or just want to keep everything you need on one device.
Create a second, FAT partition on the stick, mount the partition and copy or unpack the firmware onto it. For example:
# mount /dev/
sdX2/mnt # cd /mnt # tar zxvf
/path/to/firmware.tar.gz # cd / # umount /mnt
You might have written the
mini.iso to the USB
stick. In this case the second partition doesn't have to be created as,
very nicely, it will already be present. Unplugging and replugging the
USB stick should make the two partitions visible.
An alternative way to set up your USB stick is to manually copy the installer files, and also an installation image to it. Note that the USB stick should be at least 1 GB in size (smaller setups are possible if you follow Section 4.3.3, “Manually copying files to the USB stick — the flexible way”).
There is an all-in-one file
which contains all the installer files (including the kernel)
as well as
syslinux and its
Note that, although convenient, this method does have one major disadvantage: the logical size of the device will be limited to 1 GB, even if the capacity of the USB stick is larger. You will need to repartition the USB stick and create new file systems to get its full capacity back if you ever want to use it for some different purpose.
To use this image simply extract it directly to your USB stick:
# zcat boot.img.gz > /dev/
After that, mount the USB memory stick
which will now have
a FAT filesystem
on it, and copy a Debian ISO image (netinst or full CD/DVD) to it.
Unmount the stick (
umount /mnt) and you are done.
If you like more flexibility or just want to know what's going on, you should use the following method to put the files on your stick. One advantage of using this method is that — if the capacity of your USB stick is large enough — you have the option of copying any ISO image, even a DVD image, to it.
We will show how to set up the memory stick to use the first partition, instead of the entire device.
Since most USB sticks come pre-configured with a single FAT16 partition, you probably won't have to repartition or reformat the stick. If you have to do that anyway, use cfdisk or any other partitioning tool to create a FAT16 partition, install an MBR using:
# install-mbr /dev/
The install-mbr command is contained in the
# mkdosfs /dev/
Take care that you use the correct device name for your USB stick. The
mkdosfs command is contained in the
In order to start the kernel after booting from the USB stick, we will
put a boot loader on the stick. Although any boot loader
lilo) should work, it's convenient to use
syslinux, since it uses a FAT16 partition and can
be reconfigured by just editing a text file. Any operating system
which supports the FAT file system can be used to make changes to the
configuration of the boot loader.
syslinux on the FAT16 partition on your USB
stick, install the
mtools packages on your system, and do:
# syslinux /dev/
Again, take care that you use the correct device name. The partition
must not be mounted when starting syslinux. This
procedure writes a boot sector to the partition and creates the file
ldlinux.sys which contains the boot loader code.
Mount the partition
and copy the following installer image files to the stick:
linux (kernel binary)
initrd.gz (initial ramdisk image)
You can choose between either the text-based or the graphical version
of the installer. The latter can be found in the
subdirectory. If you want to rename the files, please note that
syslinux can only process DOS (8.3) file names.
Next you should create a
file, which at a bare minimum should contain the following line (change
the name of the kernel binary to “
if you used a
default vmlinuz initrd=initrd.gz
For the graphical installer you should add
vga=788 to the
line. Other parameters can be appended as desired.
To enable the boot prompt to permit further parameter appending, add a
prompt 1 line.
If you used an
hd-media image, you should now copy the ISO file of a
Debian ISO image onto the stick. When you are done, unmount the USB memory stick
 Don't forget to set the “bootable” bootable flag.
You can use either a netinst or a full CD/DVD image (see
Section 4.1, “Official Debian GNU/Linux installation images”). Be sure to select one that fits.
Note that the “netboot
mini.iso” image is
not usable for this purpose.