Anyone know why this doesn't work? Is this user error, AUFS feature or bug maybe: rac@tecraS1:~/tmp$ mkdir orig tmp au rac@tecraS1:~/tmp$ sudo mount -t tmpfs none tmp rac@tecraS1:~/tmp$ sudo chown -R rac tmp rac@tecraS1:~/tmp$ echo hello > orig/hello rac@tecraS1:~/tmp$ sudo mount -t aufs -o br=tmp:orig none au rac@tecraS1:~/tmp$ ls -al au total 8 drwxrwxrwt 4 rac root 100 2011-01-06 13:53 . drwxr-xr-x 5 rac rac 4096 2011-01-06 13:52 .. -rw-r--r-- 1 rac rac 6 2011-01-06 13:53 hello rac@tecraS1:~/tmp$ rm au/hello rm: cannot remove `au/hello': Operation not permitted rac@tecraS1:~/tmp$ Seems the aufs files were created as root and user has no access to them: rac@tecraS1:~/tmp$ sudo rm au/hello rac@tecraS1:~/tmp$ ls -al tmp total 4 drwxrwxrwt 4 rac root 120 2011-01-06 13:53 . drwxr-xr-x 5 rac rac 4096 2011-01-06 13:52 .. -r--r--r-- 2 root root 0 2011-01-06 13:53 .wh.hello -r--r--r-- 2 root root 0 2011-01-06 13:53 .wh..wh.aufs drwx------ 2 root root 40 2011-01-06 13:53 .wh..wh.orph drwx------ 2 root root 40 2011-01-06 13:53 .wh..wh.plnk rac@tecraS1:~/tmp$ OS is the latest Lucid with 2.6.35-23 stock kernel. No idea about aufs version. Using sudo chown -R rac tmp/.wh* fixes the problem. Thanks for looking.