Backup
The organic design backups are created daily by User:Bender, compressed to .tgz and distributed over SSH to various other domains.
- See news on 20 November 2006 regarding changeover to LZMA (.t7z)
- See news on 23 November 2006 regarding 7z server backups which can be unpacked the same as our template in Debian Conversion
About LZMA
LZMA is an extremely good compression method which compresses our backups to about one third of the size of the gzip or bzip. I have tested it with the free 7-zip file manager from www.7-zip.org and od-wiki-db-2006-11-20 is 268MB uncompressed, 54.9MB gzipped and only 21.7MB as a 7z! But I'm unable to get the Debian port to work due to dependency issues with low level C libraries that I don't want to mess with.
- I've found a standalone version at http://sourceforge.net/projects/p7zip and that's compressed it to 24.8MB, not quite as small as the windows one, but still very good.
- Using switches -t7z -m0=lzma -mx=9 has got it down to 21.1MB - slightly smaller than the windows version :-)
Statistics
7Zip is extremely good at compressing wiki data compared to other algorthims, perhaps due to compressing the history more efficiently, here's a size comparison for compressing a server image which is a standard linux file structure containing no database or web site content.
- Uncompressed: 517MB
- 7z: 122MB
- RAR: 140MB
- Bzip2: 176MB
- Gzip: 197MB
- Zip: 197MB
