Moving from Rsync on Unix to Rsync on MacOSX

I use rsync alot on unix machines. It is a versatile tool that allows you to:

• save bandwith: when synchronizing multiple machines, it will only the changes, optionally compressing the files with the '-C' option
• make incremental backups: using the --link-dest option, you can synchronize your data everyday to a new directory (backup-dayX) and avoid that it will copy all data and take up diskspace for every backup.

Rsync is by default included on MacOSX. But using when rsync on mac, there a few caveats:

• your owners might get garbled: if your disk has the option 'Ignore ownership on this volume', then when restoring the files, the ownership will not be correct. Use 'Get Info', to correct the setting. (http://terminalapp.net/backups-rsync-and-link-dest-not-working/). Or use vdsutil on the commandline.

• extra flags are lost: Mac filesystem has a notion of data and resource forks. Also the HSFS filesystem has extended attributes. So if you are synching with a samba or other non-mac filesystem aware system, this information will be lost. Apple provides a 'rsync -E' command for this.

-E, --extended-attributes Apple specific option  to  copy  extended  attributes,  resource forks,  and  ACLs.   Requires at least Mac OS X 10.4 or suitably patched rsync.

• bootable and other nice to haves: If you really also want to pertain boot flags and other things, have a look at RsyncX (http://archive.macosxlabs.org/rsyncx/rsyncx.html). It served in the past as rsync GUI and replacement until Apple got it right . A description can be found at http://hackint0sh.org/forum/showthread.php?t=25