Theresa--
this should help narrowing down where the problem is. Try running it to
the dummy disk first, then with the MML. If you still have problems,
holler-- I've been down this road before.
-lisa
Here is the technical document from the Oracle metalink site that talks
about Oracle 9i and how it works with a 3rd party tape vendor (TDP).
Backup and Recovery - Recovery Manager (RMAN) Library Index
Type: Note
Doc ID:
131865.1
Score: 32%
Modified Date:
18-NOV-2002
Status: PUBLISHED
Platform: Generic issue
Product: Oracle
Server - Enterprise Editio
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Bookmark
Fixed font
Go to End
Doc ID:
Note:188619.1
Subject:
Dynamic Loading of Libraries Using SBT_LIBRARY for
RMAN Backups in Oracle 9i
Type:
BULLETIN
Status:
PUBLISHED
Content Type:
TEXT/PLAIN
Creation Date:
10-MAY-2002
Last Revision Date:
23-OCT-2002
INTRODUCTION
-------------
In most Recovery Manager backup, restore and recover scripts when a
channel of type 'SBT' is allocated to perform backups it means that a
tape storage is being used to store written backup information during a
Recovery Manager backup operation that can be used to restore and
recover from.
SCOPE & APPLICATION
--------------------
This article is intended for all Recovery Manager Users of Oracle 9i.
The scope of this bulletin covers aspects of how libraries are linked in
dynamically in Oracle 9i, the purpose of the SBT_LIBRARY parameter,
the libobk.so and the Oracle Disk Manager (libodm9.so) library.
Consider the following backup script
Example
=======
run {
set command id to '${HOST}_${ORACLE_SID}';
allocate channel c1 type 'SBT_TAPE'
parms 'ENV=(NSR_SERVER=SHMT.US.ORACLE.COM,
ORACLE_HOME=${ORACLE_HOME},
NSR_CLIENT=${THE_CLIENT},
NSR_DATA_VOLUME_POOL=Full,
NSR_COMPRESS=FALSE,
NSR_DEBUG_FILE=${LOG_FILE}.nsr)'
;
backup full
format '${HOST}_${The_Date}_df_%d_%s_%p'
(database filesperset=3
);
When the above backup script is executed, RMAN submits the backup request
to
the Oracle server session which is actually the session that is
performing
the backup. This Oracle server session in turn identifies the output
channel
as a MML (Media Management device) and then makes a request to the
Media Manager (example Legato, Veritas, Tivoli etc) to write the output
into a backupset onto the tape media.
Before you can use RMAN to perform backups to sequential media such as
tapes,
the third party vendor API of your choice needs to first be linked or
integrated with Oracle.
How is Oracle linked in 9i
---------------------------
In Oracle 9i, Oracle loads media management libraries dynamically
when an SBT channel is allocated and the SBT_LIBRARY option is not used
in the PARMS environment variable.
Oracle will always be linked with two versions of the SBT library of
which one
is statically linked and this is also known by default as the dummy SBT
library which
will return a -1 on sbtinto() or any sbt calls. The second library is
the
oracle's disk SBT library.
How does Oracle determine which library to use when SBT channels are
allocated
using Recovery Manager
When a channel is allocated using RMAN, the channels are allocated using
the following algorithm which is used to determine the order of
precedence
in loading a library
1.If an SBT_LIBRARY is defined in the Allocate channel or Configure
Channel
command then the predefined library specified is loaded.
If no SBT_LIBRARY parameter is used in the PARMS parameter , RMAN will
attempt to load with the following order of precedence which is firstly
1) Attempt to load the libobk.so library
2) If step (1) above fails, then the statically linked SBT library
which is the libobk.a library is attempted to be used
3) If both the step (1) and (2) attempts fail, then a trace file is
generated in the user_dump_destination directory
What happened to libobk.so?
---------------------------
The existence of this library and the change in its usage is documented
in the
Oracle9i Recovery Manager User's Guide Release 1 (9.0.1) Part Number
A90135-01
In Oracle 9i, the libobk.so library is no longer a part of the standard
Oracle installation as in previous releases. It is recreated by
installing third-party media management software.
In addition, the libobk.so library is installed by the third party media
software. On Sun Solaris for example, Oracle loads this library when SBT
channels are allocated and if for any reason the library is not found
it signals a "Media Management library not found" error.
How Do I Use The Dummy SBT Library
-----------------------------------
In order to use the dummy SBT library all you would need to do is to
allocate
an SBT channel with the PARMS 'SBT_LIBRARY=oracle.disksbt' option.
There is no additional steps required like relinking or moving the
libobk.so
or manually copying the libdsbtsh8.so to libobk.so.
How Do I Test to See If The Media Management Library was successfully
loaded
------------------------------------------------------------------------------
In order to test to see whether the Media Management Library was
correctly
loaded you can allocate a channel by using the PARMS parameter
SBT_LIBRARY
which will force the loading of your MML library.
For example if you were using Legato and the libnwora library from Legato
was symbolically linked and pointed to the $ORACLE_HOME/lib/libobk.so
then you
would run a script similar to the following
run
{
allocate channel c1 device type sbt
PARMS='SBT_LIBRARY=/oracle/lib/libobk.so',
PARMS='ENV=(NSR_SERVER=SHMT.US.ORACLE.COM, NSR_CLIENT=${THE_CLIENT}
NSR_GROUP=tape)';
This can be useful when Oracle fails to successfully load the statically
linked library and
errors such as the following is generated.
ORA-19557: device error, device type: SBT_TAPE, device name:
ORA-27211: Failed to load Media Management Library
Additional information: 2
OR
If you notice errors in the the trace file in the user dump destination
such as
SKGFQ OSD: Error in function sbtinit on line 2272
SKGFQ OSD: Look for SBT Trace messages in file
/oracle/rdbms/log/sbtio.log
SBT Initialize failed for oracle.static
What is libodm9.so?
---------------------
This is a new library introduced in Oracle 9i. It is a disk management
interface defined by Oracle to manage disk and I/O performance.
When the file system or logical volume is ODM enabled, Oracle 9i
automatically utilizes the ODM interface. It is used by Oracle to manage
disk rather than use the C file routines.
For a detailed discussion on the functionality and use of ODM, pleasae
refer
to the following URL on OTN
http://technet.oracle.com/deploy/availability/techlisting.html#DS
References
-----------
<BUG 1621783>
If you are using Veritas and need more information on libodm9
please log on to Veritas Tech Support page at www.veritas.com
Following are reference materials that discusses known issues
on the use of libodm9.so with Veritas
http://seer.support.veritas.com/docs/239916.htm
Veritas TechNote ID:239916
----------------------------
How to Verify that the Oracle Disk Manager (ODM) is functioning
http://seer.support.veritas.com/docs/241482.htm
Veritas TechNote ID:241482
---------------------------
After enabling Oracle Disk Manager (ODM), connecting to an Oracle
instance results in error. Correction to the Veritas Database
Edition 3.0 Administrator's Guide
.
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