One problem I have with the frequent releases is the 3+Gb to download several times a month. Being in a land of download limits, where 3GB is considered a large chunk of your monthly usage, this hurts.
After some consideration I decided that the distribution DVDs probably contained much that was common between releases, so why not only download what was new. To test this out I've written a block based differencer program. It creates a 'difference' file between two images (well files really). It allows blocks to be moved, and produces the (AFAICT) smallest set of unique blocks and a block move guide for building the destination file from the original file. Applying this to the distributions that I have recently acquired: In its default configuration, using Solaris Developer Edition 05/07 as the base the difference file to SXCE68 is 1,610,303,488 bytes (and if zipped, drops to 1,454,403,799 bytes). From DE05/07 to SXCE69 is 1,622,497,280 bytes (1,465,171,929 after zipping). Finally from SECX68 to SECX69 was only 1,047,345,152 bytes (944,794,353 after zipping). It can produce smaller difference files at the expense of much larger computation/memory usages (typically 10% smaller can be achieved). I'll gladly give this tool to the community if we can end up with smaller downloads, Saving my, and hopefully others, download limit for other more productive things. Is this possible? I know in many places around the world Internet access is expensive for large transfers. This message posted from opensolaris.org
