Mac OS X Extended Attributes Support

Nate Gray has written a cool utility called Backup Bouncer that tests a copy utility's ability to deal with various kinds of metadata.

10.4

Using tar, these are the results on a Tiger (10.4.11) box:

dustin@schwarz ~/Desktop/release-0.1.3 $ sudo tar -C /Volumes/Src/ -cf - . | sudo tar -C /Volumes/Dst/ -xf - 
tar: ./05-timestamps/some-file: time stamp 2010-01-01 01:01:00 is 34674839 s in the future
dustin@schwarz ~/Desktop/release-0.1.3 $ sudo ./bbouncer verify -d /Volumes/Src /Volumes/Dst/
Verifying:    basic-permissions ... ok (Critical)
Verifying:           timestamps ... ok (Critical)
Verifying:             symlinks ... ok (Critical)
Verifying:    symlink-ownership ... ok 
Verifying:            hardlinks ... ok (Important)
Verifying:       resource-forks ... 
   Sub-test:             on files ... ok (Critical)
   Sub-test:  on hardlinked files ... ok (Important)
Verifying:         finder-flags ... ok (Critical)
Verifying:         finder-locks ... FAIL 
Verifying:        creation-date ... FAIL 
Verifying:            bsd-flags ... FAIL 
Verifying:       extended-attrs ... 
util/test-runner: line 1: xattr-util: command not found
util/test-runner: line 1: xattr-util: command not found
util/test-runner: line 1: xattr-util: command not found
   Sub-test:             on files ... ok (Important)
   Sub-test:       on directories ... FAIL (Important)
   Sub-test:          on symlinks ... FAIL 
Verifying: access-control-lists ... 
   Sub-test:             on files ... ok (Important)
   Sub-test:              on dirs ... ok (Important)
Verifying:                 fifo ... ok 
Verifying:              devices ... ok 
Verifying:          combo-tests ... 
util/test-runner: line 1: xattr-util: command not found
util/test-runner: line 1: xattr-util: command not found
util/test-runner: line 1: xattr-util: command not found
   Sub-test:  xattrs + rsrc forks ... ok 
   Sub-test:     lots of metadata ... FAIL 

I assume that the extended-attributes tests are failing simply because there is no support on the system, as shown by the "command not found" errors, rather than because tar has failed to copy them.

10.5

Here are the results on a Leopard (10.5.5) box. Tar's performance on Mac file system attributes has improved in a few areas.

$ sudo ./bbouncer verify -d /Volumes/Src /Volumes/Dst/
Verifying:    basic-permissions ... ok (Critical)
Verifying:           timestamps ... ok (Critical)
Verifying:             symlinks ... ok (Critical)
Verifying:    symlink-ownership ... ok 
Verifying:            hardlinks ... ok (Important)
Verifying:       resource-forks ... 
   Sub-test:             on files ... ok (Critical)
   Sub-test:  on hardlinked files ... ok (Important)
Verifying:         finder-flags ... ok (Critical)
Verifying:         finder-locks ... FAIL 
Verifying:        creation-date ... FAIL 
Verifying:            bsd-flags ... ok 
Verifying:       extended-attrs ... 
   Sub-test:             on files ... ok (Important)
   Sub-test:       on directories ... ok (Important)
   Sub-test:          on symlinks ... FAIL 
Verifying: access-control-lists ... 
   Sub-test:             on files ... ok (Important)
   Sub-test:              on dirs ... ok (Important)
Verifying:                 fifo ... ok 
Verifying:              devices ... ok 
Verifying:          combo-tests ... 
   Sub-test:  xattrs + rsrc forks ... ok 
   Sub-test:     lots of metadata ... ok