Ottavio Caruso <ottavio2006-usenet2...@yahoo.com> writes: > On 6 April 2014 23:14, Aleksej Saushev <a...@inbox.ru> wrote: >> If we want to use this definition, I'd argue that "live USB" in your >> sense is wrong approach to attack this particular problem. >> "No changes allowed" is rather strange for an educational platform, >> it means that you cannot save your work across reboots (so that you >> could revisit it in a week or in a month, for instance) except on >> another medium (which is, most probably, another USB pen drive). > > Well, that's exactly what is expected: you lend a USB pen to 10 year > old and you don't want him/her to scr*w up with the pen because next > week you're going to hand it over to some other kid. You just want to > give a presentation of your project and that's it.
I'm not native English speaker either, yet given that I've heard words "screw it (up)" in old movies intended for school age audience, they are definitly not obscene. Anyway, what do you call "screw it up"? If a talented boy decides to disassemble it to look what is inside, you're not going to repair it. If he runs "rm -rf /" and waits till it erases files into his home directory, repair takes getting into root shell and running a command to erase what remains and copy user skeleton into now empty home directory. If he is talented enough to break into the root shell to run fdisk or anything else to write to the device, you cannot stop it. Besides, even in this case restoring your USB pen takes five minutes of your machine time (not your personal time even!) to write that single gigabyte of initial image to reset it all back. > Besides, a traditional read/write installed system on a USB2 pendrive > is damn slow. A compressed filesystem like squash or a more > old-fashioned cloop is way faster. What is this strange use case that requires really fast reads and writes? Movies are fine to watch from SDHC card. Music is more that just fine to listen, all "high-end" MP3 players use this technology not to mention those you buy for 10-20 EUR. You're not going to win TPC mark or run quantum chemistry calculations with avergage commodity hardware in any case. > This doesn't rule out that you can partition the usb drive and make > some part of the fs permanent. Once could mount /usr/pkg and /home on > separate partition and have a fully functional hybrid installation. > > Knoppix and Casper (Ubuntu) use FUSE to back up changes to a permanent > location at some intervals. Damn Small Linux uses a clever, poorman's > script to back up /home and /etc to a file and restore them upon boot. Sure, there was even linux system based on CD-R and CD-RW that jumped through the hoops to overcome limitations of CD hardware in order to allow users some limited form of persistence. Why is that needed with medium that is easily rewritable? Are you trying to create more problems in order to solve them and show your heroism. You know what? I can only congratulate you that you have screwed this project up. It could be short, interesting, and fun. You could have learnt something useful while working on it. Instead you have turned it into boring corporate-style task by introduction of requireiments irrelevant (if not harfmul) to end users. All the stuff that really matters: the end software, its availability through pkgsrc, and its portability to NetBSD wasn't even discussed. -- HE CE3OH...
