Preparing a Debian/Ubuntu mirror for Kabul
	Part I. Miscellaneous subjects (and those still to be sorted)

For a programme to promote Open Source Awareness in Afghanistan, a colleague of mine will travel to Kabul University to teach general ICT security. For his workshops he needs an Ubuntu mirror, and likely a Debian mirror too.

Problem is: Afghanistan doesn't seem to have such a mirror. And the 800-or-so GB of a combined debian/ubuntu mirror would take about 71 hours to download, if my figures on available bandwidth still apply. Downloading only during the night so as not to hinder people reading mail, that would translate to nine days or so.

OTOH, a traveller from Europe with a one TB hard disk in their luggage may fly to Afghanistan in 10 hours (airport hassle included), and thereby transfer 27 MByte/s. Awful latency, but good bandwidth.

Preparing the external disk for boot

Procedure 8. Put Debian on an external harddisk

Partitioning
Connect the disk to a USB port and power it up. Then put a partition table on it. Mine looks like this:
sudo fdisk -l /dev/sdc Disk /dev/sdc: 2000.4 GB, 2000398934016 bytes 255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 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 Disk identifier: 0x95db3a6d Device Boot Start End Blocks Id System /dev/sdc1 * 2048 1026047 512000 83 Linux /dev/sdc2 1026048 210741247 104857600 5 Extended /dev/sdc3 210741248 3907029167 1848143960 83 Linux /dev/sdc5 1028096 126857215 62914560 83 Linux /dev/sdc6 126859264 168802303 20971520 83 Linux /dev/sdc7 168804352 189775871 10485760 83 Linux /dev/sdc8 189777920 193972223 2097152 83 Linux
Adding filesystems

apprentice@pc:sudo mkswap -L swap /dev/sdc8 apprentice@pc:sudo mkfs.ext4 -L root /dev/sdc5 apprentice@pc:sudo mkfs.ext4 -L var /dev/sdc6 apprentice@pc:sudo mkfs.ext4 -L tmp /dev/sdc7 apprentice@pc:sudo mkfs.ext4 -L boot /dev/sdc1 apprentice@pc:sudo mkfs.ext4 -L srv /dev/sdc3
Putting Debian on the disk

apprentice@pc:sudo mount LABEL=root /mnt/target/ apprentice@pc:for i in var tmp boot srv ; do sudo install -d /mnt/target/$i && sudo mount LABEL=$i /mnt/target/$i ; done apprentice@pc:sudo debootstrap --arch i386 wheezy /mnt/target/ http://osmirror.rug.nl/debian/ apprentice@pc:for i in proc sys dev ; do sudo mount -o bind /$i /mnt/target/$i ; done

A few fixes

apprentice@pc:sudo -s root@pc:/home/apprentice# chroot /mnt/target/ root@pc:/# apt-get install debian-keyring locales emacs sudo linux-image-amd64 openssh-server postfix root@pc:/# echo "afmirror" > /etc/hostname root@pc:/# touch /etc/mtab root@pc:/# adduser sysadmin root@pc:/# passwd # for root

Also add the user to /etc/sudoers

And create /mnt/target/etc/fstab like the following:

# Handcrafted fstab by Apprentice
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
UUID="73ea4561-87ae-49f2-ad83-bb072cd92e64"   /       ext4       errors=remount-ro          0     1
UUID="03d7912b-7fc7-4655-8880-bb7f554ea215"   /boot   ext4       defaults                   0     2

UUID="01b8ce4f-c19e-4822-9034-88e854d05b90"   /var    ext4       defaults                   0     2
proc                                          /proc   proc       nodev,noexec,nosuid        0     0
UUID="e6a434da-2a24-4f9a-bbf7-5eb2a4e2bcd1"   /tmp    ext4       defaults                   0     2
UUID="4bbbc961-bb5e-49b8-a612-f2e3181c4a69"   none    swap       sw                         0     0
UUID="93075563-dc88-451f-881a-a84046a89249"   /srv    ext4       defaults                   0     2
/dev/sr0        /media/cdrom0   udf,iso9660 user,noauto     0       0

Putting a bootsector on the disk

root@pc:/# apt-get install grub2

	Warning
	Although we 're in the chroot, /dev is bindmounted from the 'parent' host, so you almost certainly don't want to install to /dev/sda. I install the bootsector onto (the MBR of) /dev/sdc.

Unmount and detach
root@pc:/home/apprentice# sync root@pc:/home/apprentice# while mount|grep -q /target ; do umount $(mount|grep /target|tail -1|awk '{print $3}') ; done


Background reading		System configuration

Preparing a Debian/Ubuntu mirror for Kabul

Jurjen Bokma

Preparing the external disk for boot