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10.4: Use of Access Control Lists causes issues with tar UNIX
The tar utility in 10.4 is great in that it now supports copying of resource forks. I've used hfstar for a long while, and thought I'd switch this weekend to using the 10.4 version on a newly-acquired Intel iMac. The machine has its internal disk partitioned into three pieces: OS, Users and Media. On the OS and Media partitions, /usr/bin/tar worked fine and preserved resource forks on the backups.

On the Users partition, however, it successfully created tar archives, but without resource forks being preserved. It also generated errors of the form:
$ tar -cvf test.tar Test
Test/
tar: /tmp/tar.md.GPzLI9: Cannot stat: No such file or directory
Test/.DS_Store
tar: /tmp/tar.md.ayDXd5: Cannot stat: No such file or directory
Test/MyCD
Test/test.tar
tar: Error exit delayed from previous errors
I did some googling on the issue, and could find very little other than some mention that it might be due to disk errors. So I ran a repair with Disk Utility, and it couldn't find anything wrong with the disk.

So I then cloned the Users partition, re-formatted, and re-cloned back, and tar started working fine again. It was only after all this effort that I realized that I'd previously enabled ACL on the Users volume to share an iPhoto library in /Volumes/Users/Shared. (This process is described in a previous hint.)

As a test, I enabled ACL with:
 sudo /usr/sbin/fsaclctl -p /Volumes/Users -e
When I did so, the tar errors returned. I then switched ACL off with:
 sudo /usr/sbin/fsaclctl -p /Volumes/Users -d
With ACL disabled on the volume, the tar errors disappeared again.

So be warned, if you intend to use tar to back up volumes with ACL enabled, then don't! You will fail to back up resource forks on the volume. My suggestion would be to disable ACL prior to back up if using tar, and then re-enable ACL post-backup. What this does to any ACL permissions that are in place, I don't know. Anyone have any ideas as to what's going on?
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10.4: Use of Access Control Lists causes issues with tar | 6 comments | Create New Account
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10.4: Use of Access Control Lists causes issues with tar
Authored by: blb on Nov 07, '06 12:50:11PM

Note that Apple definitely knows about it as I filed a bug against this issue in May 2005 (rdar://4113146) and it was closed as a dup so someday we'll see it fixed...



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10.4: Use of Access Control Lists causes issues with tar
Authored by: wackazong on Nov 07, '06 02:42:11PM

Sorry, but whats ACL?



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10.4: Use of Access Control Lists causes issues with tar
Authored by: rycardo on Nov 07, '06 05:12:52PM
ACL=Access Control Lists
It's a way to expand permissions beyond Owner, Group, Other. Also referred to as Open Directory and Active Directory.

http://www.afp548.com/article.php?story=20050506085817850


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10.4: Use of Access Control Lists causes issues with tar
Authored by: sapporo on Nov 08, '06 12:48:06AM
Also referred to as Open Directory and Active Directory.
I don't think so.

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10.4: Use of Access Control Lists causes issues with tar
Authored by: chris_on_hints on Nov 08, '06 04:59:10AM

no, active directory and open directory are other things, look on wikipedia.



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10.4: Use of Access Control Lists causes issues with tar
Authored by: gshenaut on Nov 08, '06 06:07:34AM
I think this is a fairly general problem. You may find it interesting to peruse this article on backup software for the Macintosh, and this darwin-dev mailing list thread, especially the parts after Dan Shoop weighs in and Jordan Hubbard responds.

Greg Shenaut

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