| RMAN: RAC Backup and Recovery using RMAN [ID 243760.1] |
| 修改时间 20-OCT-2010 类型 BULLETIN 状态 PUBLISHED |
"Checked for relevance on 02-JUL-2010"
RAC Backup and Recovery using RMAN
Objectives:
===========
1. Verify the database mode and archive destination.
2. Verify connectivity using sqlnet for target and catalog.
3. Determine your backup device
4. Understand how to create an RMAN persistent configuration for a RAC env.
5. Create backups to disk using
6. Backupset Maintenance using the configured retention policy
7. Restore and Recover
a. complete
b. incomplete
8. Review and understand the impact of resetlogs on the catalog.
9. RMAN Sample Commands
Configuration:
==============
This discussion is for a 2-node Oracle RAC Cluster.
The logs are being archived to their respective node.
We are allocating channels to each node to enable the autolocate feature
of RMAN in a RAC env.
1. Verify the databases are in archivelog mode and archive destination.
a. NODE 1: thread 1
SQL> archive log list;
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /u02/app/oracle/product/9.2.0/dbs/arch
Oldest online log sequence 20
Next log sequence to archive 21
Current log sequence 21
b. NODE 2: thread 2
SQL> archive log list
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /u02/app/oracle/product/9.2.0/dbs/arch
Oldest online log sequence 8
Next log sequence to archive 9
Current log sequence 9
2. Verify connectivity to the target nodes and catalog if used.
a. % setenv TNS_ADMIN $ORACLE_HOME/network/admin
b. % sqlplus /nolog
c. SQL> connect sys/[email protected] as sysdba
d. SQL> connect sys/[email protected] as sysdba
e. SQL> connect rman/[email protected]
3. Set your testing areas.
Testing HOME for logs: /u02/home/usupport/rman
Backups HOME Location: /rman/V920
4. Connect using RMAN to verify and set the controlfile persistent configuration.
The controlfiles are shared between the instances so configuring the control-
file on node 1 also sets it for all nodes in the RAC cluster.
a. Alway note the target DBID
connected to target database: V920 (DBID=228033884)
b. Default Configuration
RMAN configuration parameters are:
CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default
CONFIGURE BACKUP OPTIMIZATION OFF; # default
CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default
CONFIGURE CONTROLFILE AUTOBACKUP ON;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # default
CONFIGURE DEVICE TYPE DISK PARALLELISM 1; # default
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE MAXSETSIZE TO UNLIMITED; # default
CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/u02/app/oracle/product/9.2.0/dbs/snapcf_V9201.f'; # default
c. Make changes to the default that fit your business requirements.
Note the retention policy can be set "TO REDUNDANCY x" or it can
be set "TO RECOVERY WINDOW OF x DAYS", this is new in Oracle9i.
In this example, using PARALLELISM 2 as 2 nodes are used.
The PARALLELISM will than automaticly start 2 channels and will
use the related CONFIGURE CHANNEL for additional clauses.
CONFIGURE RETENTION POLICY TO REDUNDANCY 3;
CONFIGURE BACKUP OPTIMIZATION OFF;
CONFIGURE DEFAULT DEVICE TYPE TO DISK;
CONFIGURE CONTROLFILE AUTOBACKUP ON;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '/rman/V920/%F';
CONFIGURE DEVICE TYPE DISK PARALLELISM 2;
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1;
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1;
CONFIGURE MAXSETSIZE TO UNLIMITED;
CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/rman/V920/snapcf_V92321.f';
CONFIGURE CHANNEL 1 DEVICE TYPE DISK connect 'SYS/[email protected]';
CONFIGURE CHANNEL 2 DEVICE TYPE DISK connect 'SYS/[email protected]';
d. Review/Verify your new configuration.
RMAN configuration parameters are:
CONFIGURE RETENTION POLICY TO REDUNDANCY 3;
CONFIGURE BACKUP OPTIMIZATION OFF;
CONFIGURE DEFAULT DEVICE TYPE TO DISK;
CONFIGURE CONTROLFILE AUTOBACKUP ON;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '/rman/V920/%F';
CONFIGURE DEVICE TYPE DISK PARALLELISM 2;
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1;
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1;
CONFIGURE CHANNEL 1 DEVICE TYPE DISK CONNECT 'SYS/[email protected]';
CONFIGURE CHANNEL 2 DEVICE TYPE DISK CONNECT 'SYS/[email protected]';
CONFIGURE MAXSETSIZE TO UNLIMITED;
CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/rman/V920/snapcf_V92321.f';
5. Make a backup using the new persistent configuration parameters.
a. Backup database with differential incremental 0 and then archived logs
using the delete input option.
backup incremental level 0
format '/rman/V920/%d_LVL0_%T_%u_s%s_p%p'
database;
backup archivelog all format '/rman/V920/%d_AL_%T_%u_s%s_p%p'
delete input;
b. Backup again using differential inremental level 1
backup incremental level 1
format '/rman/V920/%d_LVL1_%T_%u_s%s_p%p'
database;
backup archivelog all format '/rman/V920/%d_AL_%T_%u_s%s_p%p'
delete input;
c. To simplify this in Oracle9i we can also use PLUS ARCHIVELOG
Note: This uses a different alorithm then backup database and
backup archivelog in separate commands.
BACKUP incremental level 0
format '/rman/V920/%d_LVL0_%T_%u_s%s_p%p'
database PLUS ARCHIVELOG format '/rman/V920/%d_AL_%T_%u_s%s_p%p'
delete input;
Algorithm for PLUS ARCHIVELOG:
1. Archive log current
2. Backup archived logs
3. Backup database level 0
4. Archive log current
5. Backup any remaining archived log created during backup
6. Backupset Maintenance using the configured retention policy
RMAN> list backup summary;
list backup by datafile;
list backup of database;
list backup of archivelog all;
list backup of controlfile;
Note: these above can be enhanced with the "until time" clause as well as
the archivelog backups using "not backed up x times" to cut down on
many copies of a log in several backupsets. Then continuing with SMR
Server Managed Recovery use the change archivelog from...until...delete
to remove old logs no longer needed on disk.
RMAN> report obsolete;
RMAN> delete obsolete;
or
delete noprompt obsolete;
RMAN> report schema;
7. Restore and Recover
Complete Recovery
a. With the database mounted on the node1 and nomount on node2 connect
to the target and catalog using RMAN.
rman target / catalog rman/[email protected]
This script will restore and recover the database completely and open.
All previous backup will still be available for use because there was
not RESETLOGS command given.
run {
restore database;
recover database;
alter database open;
}
Incomplete Recovery
Note: If you are using instance registration the database must be mounted to
register with the listener. This means you must use the current control
file for restore and recovery or setup a dedicated listener if not
already done. RMAN requires a dedicated server connection and does not
work with using instance registration before mounting the controlfile.
Using the autobackup controlfile feature requires the DBID of the
TARGET database. It must be set when the database is not mounted and
only the controlfile and spfile (in 9.2>) can be restored this way.
a. shutdown node1 and node2
b. startup nomount node2 and node1
c. start rman
> rman trace reco1.log
RMAN> connect catalog rman/[email protected]
RMAN> set dbid=228033884;
RMAN> connect target
d. Restore the controlfile from autobackup
% rman trace recocf.log
RMAN> SET DBID=228033884;
RMAN> CONNECT TARGET
RUN
{
SET CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE disk TO '/rman/V920/%F';
ALLOCATE CHANNEL d1 DEVICE TYPE disk;
RESTORE CONTROLFILE FROM AUTOBACKUP
MAXSEQ 5 # start at sequence 5 and count down (optional)
MAXDAYS 5; # start at UNTIL TIME and search back 5 days (optional)
MOUNT DATABASE;
}
e. Verify what is available for incomplete recovery. We will recover to the
highest scn log sequence and thread. We will use the log sequence in this
case. Your options are "until time", "until scn", or "until sequence".
SQL> select max(sequence#) from v$archived_log
2 where thread#=1;
MAX(SEQUENCE#)
--------------
25
SQL> select max(sequence#) from v$archived_log
2 where thread#=2;
MAX(SEQUENCE#)
--------------
13
Note: In this case the scn is greater in thread 2 sequence# 13 then in
sequence 25 from thread 1. So we will set the seqeunce to 14 for
rman recovery because log recovery is always sequence+1 to end
at +1 after applying the prior sequence.
SQL> select sequence#, thread#, first_change#, next_change#
2 from v$archived_log
3 where sequence# in (13,25);
SEQUENCE# THREAD# FIRST_CHANGE# NEXT_CHANGE#
---------- ---------- ------------- ------------
25 1 1744432 1744802
13 2 1744429 1744805
SQL> select sequence#, thread#, first_change#, next_change#
2 from v$backup_redolog
3 where sequence# in (13,25);
SEQUENCE# THREAD# FIRST_CHANGE# NEXT_CHANGE#
---------- ---------- ------------- ------------
25 1 1744432 1744802
13 2 1744429 1744805
f. If using LMT Temporary tablespace the controlfile will have the syntax
to add the tempfile after recovery is complete.
SQL> alter database backup controlfile to trace;
Example:
# Commands to add tempfiles to temporary tablespaces.
# Online tempfiles have complete space information.
# Other tempfiles may require adjustment.
ALTER TABLESPACE TEMP ADD TEMPFILE '/dev/usupport_vg/rV92B_temp_01.dbf'
SIZE 41943040 REUSE AUTOEXTEND OFF;
# End of tempfile additions.
#
g. Since log sequence 13 thread 2 next_change# is 3 changes ahead of thread 1
sequence 25 we are using dequence 14 to stop recovery. This will restore
the datafiles and recover them completely using the online logs.
run {
set until sequence 14 thread 2;
restore database;
recover database;
alter database open resetlogs;
}
8. Review and understand the impact of resetlogs on the catalog.
RMAN> list incarnation of database V920;
Note: After resetlogs there are 2 incarnations in the recovery catalog. Only
one incarnation can be current at one time for a given dbid. The Inc Key
keeps track of the database incarnations.
List of Database Incarnations
DB Key Inc Key DB Name DB ID CUR Reset SCN Reset Time
------- ------- -------- ---------------- --- ---------- ----------
2656 2657 V920 228033884 NO 1 29-MAY-03
2656 3132 V920 228033884 YES 1744806 13-JUN-03
9. RMAN Sample Commands
a. With a dedicated listener (not using instance registration)
restoring the controlfile.
run {
allocate channel d1 type disk connect 'sys/[email protected]';
allocate channel d2 type disk connect 'sys/[email protected]';
set until sequence 14 thread 2;
restore controlfile;
alter database mount;
release channel d1;
release channel d2;
}
b. Backup Archivelog
backup archivelog all not backed up 3 times;
backup archivelog until time 'sysdate-2' not backed up 2 times;
![Partitioning Concepts[图]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=)