Problems with non system permissions

Question

just example:
OS X Lion 10.7.4
[code]ls -la /Volumes/ | grep TM
drwxrwxr-x   7 _unknown  _unknown    306  2 авг 14:50 TM[/code]
Then:
[code]chown -R root:admin /Volumes/TM[/code]
result 0:
[code]ls -la /Volumes/ | grep TM
drwxrwxr-x   7 _unknown  _unknown    306  2 авг 14:50 TM[/code]
volume is read-write hfs+ fs now
If I reformat that one so will watch _unknown user and group at that one.
[code]ls -la /Volumes/ | grep TM
drwxrwxr-x   7 _unknown  _unknown    306  2 авг 14:50 TM[/code]
why?

Answer 1

Solved.
It's not "problem".
That one is watched when on the volume we see a "ignore ownership on this volume" flag.
if disable that flag so we won't watch _unknown users/groups.