How to Loopback Mount a File That Is Usually Not Visible in a Labeled Zone

This procedure enables a user in a specified labeled zone to view files that are not exported from the global zone by default.

Before You Begin

You must be in the System Administrator role in the global zone.

1. Halt the zone whose configuration you want to change.

   # zoneadm -z zone-name halt

2. Loopback mount a file or directory.

   For example, enable ordinary users to view a file in the /etc directory.

   # zonecfg -z zone-name
   add filesystem
   set special=/etc/filename
   set directory=/etc/filename
   set type=lofs
   add options [ro,nodevices,nosetuid]
   end
   exit

3. Start the zone.

   # zoneadm -z zone-name boot

In this example, the security administrator enables testers and programmers to check that their local passwords are set. After the sandbox zone is halted, it is configured to loopback mount the passwd file. After the zone is restarted, regular users can view the entries in the passwd file.

# zoneadm -z sandbox halt
# zonecfg -z sandbox
add filesystem
set special=/etc/passwd
set directory=/etc/passwd
set type=lofs
add options [ro,nodevices,nosetuid]
end
exit
# zoneadm -z sandbox boot