[zokeinli] Ubuntu on a USB stick

Some notes on installing Ubuntu 12.04 Precise Pangolin onto a USB thumb drive: Sandisk Cruzer Fit 4 GB.

Slightly surprising that the size of the disk is actually about 4*10^9, not 4*1024^3; I had previously assumed Flash ROMs are built in powers of 2 like RAM.

Write bandwidth 30 Mb/s, read bandwidth 130 Mb/s ; faster than USB 1.1 (12 Mb/s) but considerably slower than USB 2.0 theoretical maximum of 480 Mb/s.

Tried both, but eventually chose Xubuntu over Ubuntu.  Hope is that fewer packages mean fewer updates, conserving persistent space.  Also Xmonad is easier to get working with Xubuntu.

Created usb stick with usb-creator-gtk version 0.2.34 on Ubuntu 11.10 Oneirec.  Had major problems when creating large persistent files; the program would suddenly quit with no apparent reason, leaving the ISO image mounted in a tmp directory.  Eventually, the right thing is to only create a small one, then delete it and create a larger one with the same name (casper-rw) dd if=/dev/zero, then losetup, then mkfs.ext2.  (Avoid journal to avoid many writes to disk?)

Workaround for apt failure
48xubuntu_maybe_ubiquity: 6: .: Can't open /scripts/casper-functions

cd / ; sudo ln -s /usr/share/initramfs-tools/scripts

Workaround for
run-parts: executing /etc/kernel/postinst.d/zz-update-grub 3.2.0-29-generic /boot/vmlinuz-3.2.0-29-generic
/usr/sbin/grub-probe: error: cannot find a device for / (is /dev mounted?).

apt-get purge grub2-common

It boots fine without grub.

Install aptitude because I prefer it.  When did apt start installing recommended packages by default?  Use -R

sudo apt-get purge smbclient thunderbird language-pack-gnome-fr-base language-pack-gnome-es-base language-pack-gnome-pt-base language-pack-es-base language-pack-pt-base gnumeric-common language-pack-fr-base language-pack-gnome-zh-hans-base language-pack-zh-hans-base libsmbclient samba-common-bin

Use deborphan -n -a to purge unneeded packages.  I'm unsure about how recommended (-n) some packages are.

Aptitude full-upgrade.  Took an hour because of slow disk IO speed.  Eats up a gigabyte of persistent space.