Many times RMAN session hangs or gave different types of errors. The investigation cannot be done with log files generated. We need to debug rman session in order the performance issues or the errors. With debugging a detailed trace file is generated where we can easily find the performance issue and errors
The RMAN Debug command generates more extensive output, use debugging for the following purposes.
• To see the actual programs generated by RMAN
• To determine the failure of RMAN Command
The RMAN debug option can be used to trace RMAN session, and it will be very useful to troubleshoot an issue.
rman target / catalog user/[email protected] debug trace rman.trc log rman.log
rman target / debug trace rman.trc log rman.log
The rman.trc will contains all the debug information
cat rman.log Recovery Manager: Release 220.127.116.11.0 - Production on Thu Apr 13 15:21:05 2015 Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved. RMAN-06005: connected to target database: TEST (DBID=432525555) RMAN>RMAN-03090: Starting backup at 13-APR-15 RMAN-06009: using target database control file instead of recovery catalog RMAN-08030: allocated channel: ORA_DISK_1 RMAN-08500: channel ORA_DISK_1: SID=618 device type=DISK RMAN-08008: channel ORA_DISK_1: starting full datafile backup set RMAN-08010: channel ORA_DISK_1: specifying datafile(s) in backup set RMAN-08522: input datafile file number=00031 name=/app/oracle/TEST/oradata/data01.dbf RMAN-08522: input datafile file number=00033 name=/app/oracle/TEST/oradata/data02.dbf RMAN-08522: input datafile file number=00038 name=/app/oracle/TEST/oradata/data03.dbf RMAN-08522: input datafile file number=00039 name=/app/oracle/TEST/oradata/data04.dbf RMAN-06731: command backup:1.0% complete, time left 03:27:06 RMAN-06731: command backup:1.9% complete, time left 03:32:09
The trace file will have all information running behind the screen.
The “rman.trc” will look like below
cat rman.trc |more Recovery Manager: Release 18.104.22.168.0 - Production on Thu Apr 13 15:21:05 2015 Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved. RMAN-06005: connected to target database: TEST (DBID=432525555) RMAN>System name: SUN Node name: TESTSERV Release: 2.6.18-194.17.1.el5 Version: #1 SMP Mon Sep 20 07:12:06 EDT 2010 Machine: x86_64 Starting with debugging set to level=9, types=ALL DBGMISC: ENTERED krmksimronly [15:21:06.175] DBGSQL: CHANNEL> alter session set events '19737 trace name context forever' DBGSQL: sqlcode = 0 DBGSQL: CHANNEL> select decode(archiver, 'FAILED', 1, 0) into :archstuck from v$instance DBGSQL: sqlcode = 0 DBGSQL: D :archstuck = 0
Trace via the RMAN Channel
Another way to trace RMAN activity would be to configure the trace when configuring the RMAN channel.
1. Make sure timed_statistics = true for all performance testing.
2. set the NLS_DATE_FORMAT = ‘DD-MON-YYYY HH24:MI:SS’.
3. Configure the Channel with Trace/Debug options
trace 1 – general trace info for skg and sbt
trace 5 – verbose channel tracing of skg and sbt calls
CONFIGURE CHANNEL DEVICE TYPE
DISK DEBUG=5 TRACE 1;
CONFIGURE CHANNEL DEVICE TYPE SBT PARMS "ENV=(....) DEBUG=5 TRACE 5;
Note: (Trace is only useful for tape backup and restore tracing)
You can read more about RMAN utility at the below links
- Oracle RMAN interview questions
- RMAN backup commands
- Oracle RMAN cheat sheet
- Oracle support Note