4.3. Preparing Files for USB Memory Stick Booting
Prev  Chapter 4. Obtaining System Installation Media  Next

4.3. Preparing Files for USB Memory Stick Booting

To prepare the USB stick, we recommend to use 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 lsblk before and after inserting it. (The output of dmesg (as root) is another possible method for that.) To write to your stick, you may have to turn off its write protection switch.

[Warning] Warning

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 is lost.

4.3.1. Preparing a USB stick using a hybrid CD/DVD image

Debian installation images for this architecture are created using the isohybrid technology; that means they can be written directly to a USB stick, which is a very easy way to make an installation media. Simply choose an image (such as the netinst, CD or DVD-1) that will fit on your USB stick. See Section 4.1, “Official Debian GNU/Linux installation images” to get an installation image.

Alternatively, for very small USB sticks, only a few megabytes in size, you can download the mini.iso image from the netboot directory (at the location mentioned in Section 4.2.1, “Where to Find Installation Files”).

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: 

# cp debian.iso /dev/sdX
# sync

Information about how to do this on other operating systems can be found in the Debian CD FAQ.

[Important] Important

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.

[Important] Important

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.

To do so, use cfdisk or any other partitioning tool to create an additional partition on the stick. Then create a (FAT) filesystem on the partition, mount it and copy or unpack the firmware onto it, for example with: 

# mkdosfs -n FIRMWARE /dev/sdX3
# mount /dev/sdX3 /mnt
# cd /mnt
# tar zxvf /path/to/firmware.tar.gz
# cd /
# umount /mnt

Take care that you use the correct device name for your USB stick. The mkdosfs command is contained in the dosfstools Debian package.

[Note] Note

If you have chosen the mini.iso to be written to the USB stick, 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.

Prev  Up  Next
4.2. Downloading Files from Debian Mirrors  Home  4.4. Preparing Files for TFTP Net Booting