Making a bootable USB stick

Introduction

This procedure is to guide me through making a basic Debian+XFCE bootable USB stick.

It is heavily based on David Bremner’s procedure at http://www.cs.unb.ca/~bremner/blog/posts/bootable-usb/, but tweaked for less manual work and to add the software I want.

Procedure

1. For next time:
   • prepare the image offline and then dd it over the USB stick; the stick is too slow to do installs onto
   • configure a caching-only name server so we get access to root domain servers, rather than having to reconfigure /etc/resolv.conf for each location; don’t use bind for this
2. Attach the USB stick, identify the device and wipe it by running:

   dmesg
   

   and identify the stick, e.g. /dev/sdc.

3. Set some environment variables needed by the rest of this procedure:

   DEV=/dev/sdc
   MNT=/mnt

4. Blank the USB stick:

   dd if=/dev/zero of=$DEV bs=1M

   and wait dd until complains there is no space left on the device.

5. Partition the stick, create the filesystem and mount it by running:

   parted $DEV
   mklabel msdos
   mkpart primary ext2 1 -1
   set 1 boot on
   quit
   mkfs -t ext3 ${DEV}1
   mount ${DEV}1 $MNT

6. Install the base system by running:

   debootstrap --variant=minbase jessie $MNT http://httpredir.debian.org/debian/
   grub-install --boot-directory $MNT/boot ${DEV}1

7. Fix up some small things:

   cp /etc/fstab $MNT/etc/fstab
   blkid -p ${DEV}1 | cut -f2 -d' ' >> $MNT/etc/fstab
   vi /mnt/etc/fstab
   #  I like to set a blank password on a USB stick
   perl -pi -e 's/root:[^:]*:/root::/' $MNT/etc/shadow
   

8. Chroot into the stick by running:

   mount -o bind /dev $MNT/dev
   mount -o bind /sys $MNT/sys
   mount -o bind /proc $MNT/proc
   chroot $MNT

9. Install software:

   apt-get install linux-base linux-image-amd64 grub-pc xfce4 net-tools \
       vim-gtk man-db iceweasel console-data telnet iputils-ping \
       xfwm4-themes nmap tcpdump xfce4-goodies screen ethtool nmap \
       lvm2 lshw bind9-host bind9

10. Tailor root’s environment a bit:

    touch $MNT/root/.hushlogin
    echo 'PS1="\\h\\$ "' >> $MNT/root/.bashrc

11. Prevent NIC renaming:

    rm $MNT/etc/udev/rules.d/70-persistent-net.rules
    ln -s /dev/null $MNT/etc/udev/rules.d/70-persistent-net.rules

12. Clean up by running:

    exit
    umount $MNT/proc
    umount $MNT/sys
    #  I found a dbus-daemon process was holding /mnt/dev open
    fuser -c $MNT/dev
    kill <pids-holding-$MNT/dev/-open>
    umount $MNT/dev
    umount $MNT
    sync

    and remove the stick.

See also

• http://www.cs.unb.ca/~bremner/blog/posts/bootable-usb/
• Computing