How to copy Time Machine volume to another disk using rsync while preserving ACLs?

Solution 1:

Download rsync version 3 using Homebrew. Then you can try the "--acls" option. The rsync on Mac seems to have a slightly different command line syntax from other operating systems. You probably want to take a look at this link: http://nicolasgallagher.com/mac-osx-bootable-backup-drive-with-rsync/. It describes how to get rsync 3 and the command line arguments he uses.

I'm not an OSX user, but I back up my wife's Mac to a Linux server with rsync.

Solution 2:

rsync, at least in OS X 10.4 and following, will transfer ACL attributes if the -E option is used. See the man page.

Solution 3:

Apple currently says to use the Finder to copy Time Machine backups.

https://support.apple.com/en-gb/HT202380

My experience, in trying to copy 1TB TimeMachine backup from local disc to network disk, has been

• rsync and asr failed with errors I couldn't work out.
• Finder copy 1st attempt failed with a permissions error after an hour of examining what it was about to copy.
• Finder copy 2nd attempt succeeded. I don't recall what was different. Perhaps it was just freshly remounted.
• It took 3 days to copy 1TB.