Optimizations for Ubuntu installed on a USB drive

Question

I want to install Ubuntu 11.04 to my 16 GB fast USB flash disk (I don't want "installation" with Universal USB Installer as written on original Ubuntu site).

I want it for portable use. I wonder if there are any optimizations for that, like:

• keeping things in RAM as long as possible,
• minimizing disk writes (that's so bad for flash),
• dealing with hardware drivers when running on other computers,
• et cetera.

My requirements are:

• full "/" partition encryption (I know that /boot/ can't be encrypted)
• not using Universal USB Installer
• no extra partitions for persistent changes.

Any tips for above things, partitioning or useful system changes would be appreciated.

Answer 1

I did an ubuntu-install with exactly your three requirements (as they match mine). And I did nothing special about it, except I used the alternate Ubuntu-install to turn disk-encryption on.

I did the following:

• Download alternate iso: (use the iso with alternate in the name)
• Install it on a bootable medium (i used a smaller usb-stick with the USB-Installer, but CD is fine too)
• Boot from the install-medium
• Put your target USB-stick in and install to that location (if you are unsure which drive is correct, you should look at the disk-size)
• Enable encryption (LVM) in the installation-process
• Reboot from your newly installed Ubuntu from the USB-disk

That worked for me some years now. I can use this stick on different computers, as the hardware will be detected automatically. It is somewhat slower from USB, so I use a lightweight window-manager. LXDE or XFCE should be fine. You could add noatime,nodiratime to /etc/fstab to reduce writing to the USB. I also deactivate Swap, as most machines I use provide more than 1GB of RAM and that's enough for my needs.