System Administration Guide: Advanced Administration

What to Do If File ACLs Are Lost After Copy or Restore

Reason Error Occurred 

How to Fix the Problem 

If files or directories with ACLs are copied or restored into the /tmp directory, the ACL attributes are lost. The /tmp directory is usually mounted as a temporary file system, which doesn't support UFS file system attributes such as ACLs.

Copy or restore files into the /var/tmp directory instead.