How to Easily Make Custom Linux Install ISOs?

Jason Tilke asks: "I recently read an article which discusses HP's LinuxCOE v4. We've been wanting a system to make rolling out custom but standardized systems (in terms of package selection) and LinuxCOE seems to fit the bill. Are there any alternative that'll spit out custom ISOs which our non-technical staff can use to install a complete Linux system? Has anyone had any positive/negative experience with LinuxCOE? Are there any precautions/steps we should take to prevent us from tripping over our new changes?"

Re:Knoppix.

[pla]

I didn't have a lot of patience with what I removed or included, but once, due to dependencies, it started to remove some really base packages, and I got fed up.

I find that, for the most part, apt will warn you if you try to remove something important... But not always. When in doubt about one of the packages it shows, try checking what it does with something like:
dpkg-query -W --showformat='${Installed-Size} ${Package} ${Description} ${Status}' packagenamegoeshere
You should also run deborphan every few removals to see if you can throw away another library or three.


Also, with Knoppix, you'll eventually notice you have three un(easily)removeable sets of rather large files installed on your system - apt-get itself, locales, and kernel modules.

As one of your very last steps, delete your dpkg and apt caches (the size of those will depend on how much you installed, but can really add up if you make a lot of changes), and then just rm -rf your /var/lib/apt/lists for a whopping 85MB or so (this won't even break apt, amazingly enough! You'll just need to do an apt-get update to repair it if you ever need it again).

For the locales, put only the locale(s) you want in "/etc/locales.gen" (probably only "en_US ISO-8859-1" if you live in the US) and running "locale-gen". This will drop your /usr/lib/locale/locale-archive from 15MB to around 1MB, and then you can manually delete all the useless ones from /usr/share/locales to save another 27-29MB.

Do you want to keep 65MB worth of kernel modules around for things like ISDN/ATM/IPX/Appletalk, any FS other than EXT2/Reiser/CIFS, and support for ancient ISA cards? Most likely you plan to target a single system; boot to it and see what modules get loaded. Keep a few extra really common ones if you want, but you can easily throw away 90% of them with zero loss of functionality.


You can also find some significant savings by removing your manpages and documentation; and if you need X, do you really need the latest-and-greatest 3d accelerated drivers just to scroll your MP3 playlist, or would the relatively tiny framebuffer driver suffice? Deleting all your useless timezones helps too, but that will only buy you an extra 5MB (though as you noticed, once you pass the 100MB mark, every byte helps). You should also make friends with "strip", though at that point you really do start saving only a few KB per use. And at the tightest end of the spectrum of space-saving, a statically-linked BusyBox can singlehandledly save you 10-30MB of binaries and assorted libraries.



Finally, keep in mind that the "c" in "cloop" stands for "compressed"... Getting the FS down to around 400MB (pre-compression) means it should fit comfortably on a mini-cdr, and DSL (v3.3) itself weighs in at 124MB uncompressed. This might not so much matter if you want to do a "real" HDD-like install onto a small USB or flash drive, but if you plan to boot from readonly media, even using the "toram" option, only the compressed size matters (with enough RAM, of course).