README
======

The file mapping feature enables Oracle to map objects in the database at the
different components of the I/O storage stack starting from the file system,
the volume manager, the storage array all the way down to the physical disks.

This feature will work ONLY if mapping libraries are available for the
different storage components. A typical system would be expected to have a
library for each of the following: the file system, the volume manager, and
storage arrays.  However, it is also possible for a single mapping library to
map the entire storage stack - this is the case for the library supplied by
Oracle for EMC Symmetrix arrays.

For the latest information on supported vendors and mapping libraries, please
check MetaLink document <Note:268709.1>.

SETTING UP THE FILE MAPPING SERVICE
===================================

In order for the file mapping service to be properly initialized, root access
to the system is needed. This is required since some components of the
mapping service require system privileges to run properly.

To setup the service, the following steps are needed:

1. Create a "filemap" directory that is owned and written by root ONLY.
   For 32-bit systems, a recommended name is ORCLfmap/prot1_32 under /opt.
   For 64-bit systems, a recommended name is ORCLfmap/prot1_64 under /opt.
   This document shall refer to this "filemap" directory as $FILEMAPLOC.
   All subdirectories under $FILEMAPLOC must be owned and written by root ONLY.

2. Create the following subdirectories under $FILEMAPLOC:
   mkdir bin (location for file mapping binaries)
   mkdir etc (location for the configuration file)
   mkdir log (location for the trace files)

3. Copy fmputl and fmputlhp from $ORACLE_HOME/bin to $FILEMAPLOC/bin.
   Make sure the execute bit is set on both binaries.

4. Enable the setuid bit for fmputlhp.
   Make sure fmputlhp has execute permission for others.

5. Create filemap.ora under $FILEMAPLOC/etc. This is the configuration file
   that describes all the mapping libraries available.

   The following row needs to be created for each library:
   lib={vendor name}: {mapping library path}

   {library path} is the full path of the mapping library.

   Note that the ordering of the libraries in this file is extremely
   important. The libraries are queried based on their order in the
   configuration file.

   The file mapping service can be even started even if no mapping
   libraries are available. filemap.ora still needs to be present
   even though it is empty. The mapping service in this case is
   constrained in the sense that the live mapping information can
   not be discovered. Only restore/drop operations are allowed in
   such a configuration.

6. Create a symbolic link to the filemap directory under $ORACLE_HOME/rdbms.
   ln -s $FILEMAPLOC $ORACLE_HOME/rdbms/filemap


Note that steps 1->5 need to be executed with system privileges.

These configuration steps are done during installation of 9.2.0.3 or above
as part of root.sh. There is no need to do this manually.

HOW TO ENABLE FILE MAPPING
==========================

This feature is turned on by setting the dynamic init.ora parameter
file_mapping to TRUE.
The feature is turned off by setting file_mapping to FALSE.

Once the feature is turned on, a new Oracle background process (FMON) is
started. If the mapping service fails to start, an ORA-32052 is raised by
the background process.

For a full description of the file mapping feature, please consult the
Oracle Database Administrator's Guide.