> Others have given links (and here's a good one: > http://www.samba.org/rsync/how-rsync-works.html), but in a nutshell, > Rsync will can the file at one end calculating checksums of blocks. > At the other end, it will do a rolling checksum looking for matches - > note that this is a rolling checksum so it will detect files that > have had bits inserted or removed, thus altering the position of > later data. It will then send the differences. > > Thus, if you take a 1GB file and add a single byte at the beginning, > rsync will only have to send the checksums (and hashes used for > verification) plus the first block - it will detect that the rest of > the file has simply moved along a byte. > > Along with this, it can compress the data over the wire, use SSH to > secure it, and even has the option to restrict bandwidth usage. Not > only that, it runs multiple tasks in parallel - ie scans files > looking for changes while still transferring earlier files. All this > means that it is VERY effective over WAN links - like others, I've > been using it for many years. > > You mentioned OS X. If you use the version of Rsync provided by > Apple, then it's patched to handle HFS extended attributes if you > specify -E or --extended-attributes as an option.
Hot damn. I thought it just scanned for mtime etc. For backing up my parallels virtual hard drive, I'll go use simply rsync then... Thanks... _______________________________________________ rdiff-backup-users mailing list at [email protected] http://lists.nongnu.org/mailman/listinfo/rdiff-backup-users Wiki URL: http://rdiff-backup.solutionsfirst.com.au/index.php/RdiffBackupWiki
