I’m looking at you Ubuntu.
For some time now, the standard form for distributing a free OS (ie. Linux, *BSD) has been as a CD-ROM or DVD ISO file. You burn it to a CD, and you can boot and install from that, and also use the disk as a live CD.
There are a variety of pages with instructions on how to convert such an ISO into a bootable flash drive, and scripts and programs for linux and even for windows — for those installing linux on a windows box.
And these are great and I used one to make a bootable Ubuntu stick on my last install. And wow! It’s such a much nicer, faster experience compared to using CD that it’s silly to use CD on any system that can boot from a USB drive, and that’s most modern systems. With a zero seek time, it is much nicer.
So I now advocate going the other way. Give me a flash image I can dd to my flash drive, and a tool to turn that into an ISO if I need an ISO.
This has a number of useful advantages:
- I always want to try the live CD before installing, to make sure the hardware works in the new release. In fact, I even do that before upgrading most of the time.
- Of course, you don’t have old obsolete CDs lying around.
- Jumping to 1 gigabyte allows putting more on the distribution, including some important things that are missing these days, such as drivers and mdadm (the RAID control program.)
- Because flash is a dynamic medium, the install can be set up so that the user can, after copying the base distro, add files to the flash drive, such as important drivers — whatever they choose. An automatic script could even examine a machine and pull down new stuff that’s needed.
- You get a much faster and easier to use “rescue stick.”
- It’s easier to carry around.
- No need for an “alternate install” and perhaps easier as well to have the upgrader use the USB stick as a cache of packages during upgrades.
- At this point these things are really cheap. People give them away. You could sell them. This technique would also work for general external USB drives, or even plain old internal hard drives temporarily connected to a new machine being built if boot from USB is not practical. Great and really fast for eSata.
- Using filesystems designed not to wear out flash, the live stick can have a writable partition for /tmp, installed packages and modifications (with some security risk if you run untrusted code.)