Why should not hot backup in rman

Hi ,
Please let me know why should not take tablespace begin backup mode in rman

Hi ,
SARAT point is correct.
what do you mean backup set ? its like
A backup set contains one or more binary files in an RMAN-specific format. Each of these files is known as a backup piece. A backup set can contain multiple datafiles. For example, you can back up 10 datafiles into a single backup set consisting of a single backup piece. In this case, RMAN creates one backup piece as output. The backup set contains only this backup piece."
Thats reason all datafiles one set, all archivelogs one set, and spfile & controlfile is another set.
Let us know if anything you required.
Thanks
Murali.

Similar Messages

Frequency of Hot backups using RMAN

Hello.
After years of running various inhouse utilities to backup our Oracle databases we are now going to implement RMAN in our shop. We are running Oracle 10.2.0.4 EE databases on Solaris servers in Archivelog mode, so we'd like to perform "hot" backups. A caveat to this is that we also have "standby" databases that we manually manage via a series of scripts that works rather well and helps our CIO sleep at night.
So what we're trying to do is tackle one obstacle at a time. We'd like to implement RMAN hot backups (including archivelogs) without having RMAN remove the archivelog backups that are out there. We simply want RMAN to backup the archivelog files, we'll manage their movement and removal ourselves for the time being.
The script I have put together simply issues: Backup database plus archivelog format='/dumps/rman/F_Database_%d_set%s_%T_%U';
The configuration settngs (we want at least a 2 day recovery period) are:
RMAN configuration parameters are:
CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 2 DAYS;
CONFIGURE BACKUP OPTIMIZATION ON;
CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default
CONFIGURE CONTROLFILE AUTOBACKUP ON;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '/dumps/rman/controlfiles/%F';
CONFIGURE DEVICE TYPE DISK PARALLELISM 2 BACKUP TYPE TO BACKUPSET;
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE CHANNEL DEVICE TYPE DISK FORMAT '/dumps/rman/W_Database_%d_set%s_%T_%U';
CONFIGURE MAXSETSIZE TO UNLIMITED; # default
CONFIGURE ENCRYPTION FOR DATABASE OFF; # default
CONFIGURE ENCRYPTION ALGORITHM 'AES128'; # default
CONFIGURE ARCHIVELOG DELETION POLICY TO APPLIED ON STANDBY;
CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/xora01/app/oracle/product/10g/dbs/snapcf_glprd.f'; # default
We are using an RMAN catalog.
So my question is, if I perform the backup of the database (using the above command) once or twice a week and back-up only the archivelogs on a daily basis, would I be covered and save space at the same time? I think this might cover me as far as the archivelogs are concerned as well until my management is more comfortable with RMAN and allows us to install/use Data Guard.
Thanks for you opinions/suggestions...

Hi,
So my question is, if I perform the backup of the database (using the above command) once or twice a week and back-up only the archivelogs on a daily basis, would I be covered and save space at the same time? I think this might cover me as far as the archivelogs are concerned as well until my management is more comfortable with RMAN and allows us to install/use Data Guard.Your idea also not bad to save disk space. it is also depends on database size and space availability on your server.
or else you can go for weekly once fulll backup, remaining days incremental backups & archivelog backups.
rman incremental backups take only chanegd blocks so it wont occupy much space
1) sunday - full backup - level 0
2) monday - inc1 & arch
3) tuesday - inc2 & arch
4) wednesday - inc1 & arch
5) thursday - inc2 & arch
6) friday - inc1 & arch
7) saturday - inc2 & arch... & so on...
Thanks

Restoring a Hot backup using RMAN on a different server.

Hi
we are using oracle 10.2.0.4.0 on solaris 10 and using a separate catalog for RMAN backups.
we have taken a production db Hot backup as follows
level 0 backup on 28 th dec.
level 1 on 29,
level 1 on 30 and
level 1 on 31 st.
now today in the month of feb .
we would like to create a dev. DB on a diffent server which has diffent directory structure, i have to create a db using the above backups to setup the db like on 31 st Jan.
could you please provide the steps and advice how do i proceed.
Thansk fot the help.

Make level 0 and level 1 backups + control files backups + archived redo logs backup available on new host and use RMAN DUPLICATE.
See examples in http://download.oracle.com/docs/cd/B19306_01/backup.102/b14191/rcmdupdb.htm#i1008564
Edited by: P. Forstmann on 2 févr. 2010 22:39
Edited by: P. Forstmann on 3 févr. 2010 07:57

Hot Backup with RMAN question.

Hi all.
We want to make a full backup with RMAN every night with the db up. Version 9i in archive log mode.
My question is if with the command:
backup database plus archivelog delete input format 'MY_FORMAT_STRING';
will store all the files needed for the recovery in one file or I need to backup some other file or do more actions. The backup will be consistent?
Regards.

By using this command you are only taking the backup
all the database files plus all the archived logs
needed for point on recovery.
But still you will have to take the backup of Control
file and parameter files. Which you do by configuringi think its not
RMAN> configure controlfile autobackup off
2> ;
old RMAN configuration parameters:
CONFIGURE CONTROLFILE AUTOBACKUP ON;
new RMAN configuration parameters:
CONFIGURE CONTROLFILE AUTOBACKUP OFF;
new RMAN configuration parameters are successfully stored
RMAN> backup database
2> ;
Starting backup at 28-NOV-07
using channel ORA_DISK_1
channel ORA_DISK_1: starting full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
input datafile fno=00001 name=C:\ORACLE10G\ORACLE\ORADATA\ORCL\ORCL\SYSTEM01.DBF
input datafile fno=00003 name=C:\ORACLE10G\ORACLE\ORADATA\ORCL\ORCL\SYSAUX01.DBF
input datafile fno=00002 name=C:\ORACLE10G\ORACLE\ORADATA\ORCL\ORCL\UNDOTBS01.DB
F
input datafile fno=00004 name=C:\ORACLE10G\ORACLE\ORADATA\ORCL\ORCL\USERS01.DBF
input datafile fno=00005 name=C:\ORACLE10G\ORACLE\ORADATA\ORCL\ORCL\DATA.DBF
channel ORA_DISK_1: starting piece 1 at 28-NOV-07
channel ORA_DISK_1: finished piece 1 at 28-NOV-07
piece handle=C:\ORACLE\FLASH_RECOVERY_AREA\ORCL\ORCL\BACKUPSET\2007_11_28\O1_MF_
NNNDF_TAG20071128T151313_3NTHSTK9_.BKP comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:45
channel ORA_DISK_1: starting full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
including current controlfile in backupset
including current SPFILE in backupset
channel ORA_DISK_1: starting piece 1 at 28-NOV-07
channel ORA_DISK_1: finished piece 1 at 28-NOV-07
piece handle=C:\ORACLE\FLASH_RECOVERY_AREA\ORCL\ORCL\BACKUPSET\2007_11_28\O1_MF_
NCSNF_TAG20071128T151313_3NTHV8S5_.BKP comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:03
Finished backup at 28-NOV-07
RMAN>backup database backup controlfile as well spfile but its better backup control file separately after backing up the database plus archivelog cause a backup set info within control file which will not be in control file which is just backed up by backup database .
Khurram
null

Full Hot Backup using RMAN?

Dear all,
I want to take a full hot backup every week on sunday and the followings are the commands.
run
allocate channel ch1 type disk format '/db/BACKUP/RMAN/backup_%d_%t_%s_%p_%U.bck';
backup
incremental level 0
database
plus archivelog delete input;
backup current controlfile;
backup spfile;
release channel ch1;
I have the following questions:
1) Am I need to define a directory named as "'/db/BACKUP/RMAN/backup_%d_%t_%s_%p_%U.bck", so that the backup copies will put it here,right?
2) What format needs to be save in where and how to run it on weekly schedule basis?
3) I saw above script with "channel ch1", can I change it to "channel ch2"?
I am a beginner using RMAN, please let me know.
Best Regards,
amy

Which database version on which OS (looks like Unix/Linux)?
You have to create the directory '/db/BACKUP/RMAN', 'backup_%d...' is the filename created by RMAN.
%d Specifies the name of the database;
%t Specifies the backup set time stamp, which is a 4-byte value derived as the number of seconds elapsed since a fixed reference time. The combination of %s and %t can be used to form a unique name for the backup set;
%s Specifies the backup set number. This number is a counter in the control file that is incremented for each backup set. The counter value starts at 1 and is unique for the lifetime of the control file. If you restore a backup control file, then duplicate values can result. Also, CREATE CONTROLFILE initializes the counter back to 1;
%p Specifies the piece number within the backup set. This value starts at 1 for each backup set and is incremented by 1 as each backup piece is created;
%U Specifies a system-generated unique filename (default).
For scheduling a cron job could be defined or you use Enterprise Manager (10g and higher)
Channel name doesn't matter.
Werner

Hot backup without rman

i read someweher but confusion,i paste it here
When that happens,the non-Oracle tool might read a block in a half-updated state, so that the block which is copied to the backup media might only have been updated in its first half, while the second half contains older data.This is called a "fractured block". If this backup needs to be restored later, and that block needs to be recovered, recovery will fail because that block is not usable.
The 'alter tablespace begin backup' command is our solution for the
fractured block problem. When a tablespace is in backup mode, and a
change is made to a data block, instead of logging just the changed
bytes to the redo log, we also log a copy of the entire block image
before the change, so that we can reconstruct this block if media
recovery finds that this block was fractured.
my confusion
firts time changes we log the entire block image and after that changes bytes are applied only .redo log file also copied by OS and suppose it comes into situation where first half of block is copied and during that second half block is changed after that OS copy the second half ,a mismatch in head and tail scn,then how it is not fractured block?
tks & regards
umaisi

If you try to copy e.g. with file system tools, yes.what do you mean by file system tools.
i am not clearing the picture i again try to clear the picture please clear me!!
i have confusion when we start online backup the block may be in fractured mode
when copying block from datafile,but why the block is not in fractured mode when
copying block from archive log file.The reason is that before changes in a block
LGWR writes whole block to the log file and after that again any changes in the
same block will record only those chnages.
ok it is clear to me.
confusion now come here
suppose i start online backup and start copying datafile and archivelog file from os ,
1)i modify a block 'A', LGWR first time writes that whole block 'A' to log file before changes.
2)now copying the file is in progress for that block 'A' it copy the block 'A'
first half due to os capability .
3)during that i again modify the block 'A' its second time modifiation and only changes are applied to log file.
4)OS comes to copy the remaining part of block 'A' now this block 'A' second part changed.
now how it will be consistent?why it is not fractured like it is fractured with the case of copying datafile but now with archive log file why not it is frctured?
next problem is why for online backup archive log should be enabled?
SQL> shutdown
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount
ORACLE instance started.
Total System Global Area 171966464 bytes
Fixed Size 787988 bytes
Variable Size 145750508 bytes
Database Buffers 25165824 bytes
Redo Buffers 262144 bytes
Database mounted.
SQL> alter database noarchivelog
2 /
Database altered.
SQL> alter database open
2 /
Database altered.
SQL> alter tablespace system begin backup
2 /
alter tablespace system begin backup
ERROR at line 1:
ORA-01123: cannot start online backup; media recovery not enabled
tks & regards
umaisi

Restore hot backup using RMAN?

Hi,
We are taking hotbackup using rman level0,leve1,level2. Now i want to restore level 0 first then level 1 and level 2.. how to restore like this
Thanks in advance

You don't have to explicitly restore each L0, L1 etc backup.
When you specify a SET UNTIL, RMAN identifies the backups (starting with the latest L0 before the SET UNTIL) that are to be restored and attempts to restore them.
If the backups were to disk and are no longer on disk (i.e. you have moved them to tape), you have to ensure that the backups are made available (by copying them back from tape to disk).
You can use RESTORE DATABASE VALIDATE and RESTORE ARCHIVELOG VALIDATE to identify the backups that are required.
See http://hemantoracledba.blogspot.com/2010/03/misinterpreting-restore-database.html
Hemant K Chitale

Missing logfiles when hot backup is taken using RMAN

Hello All,
I am having the below situation .Please help to clarify.
I have taken hot backup using RMAN. Database is in Archivelog mode. It doesn't take backup of online redo logs. The status of my redo logs are as below. All are not archived.
/u01/app/oracle/oradata/redo01.log ----Active---Not Archived
/u01/app/oracle/oradata/redo03.log ----Active---Not Archived
/u01/app/oracle/oradata/redo03.log----Current---Not Archived
Now, I am using the backup to restore a database on another machine. But as the logs are not archived, I may miss some data.
How can I get the data also?
Regards
VJ..

I have taken hot backup using RMAN. Database is in Archivelog mode. It doesn't take backup of online redo logs. The status of my redo logs are as below. All are not archived.
/u01/app/oracle/oradata/redo01.log ----Active---Not Archived
/u01/app/oracle/oradata/redo03.log ----Active---Not Archived
/u01/app/oracle/oradata/redo03.log----Current---Not Archived
Now, I am using the backup to restore a database on another machine. But as the logs are not archived, I may miss some data.
How can I get the data also?If the redo log status is still "ACTIVE" that mean, still archiving is in progress,
You can give even
SQL> alter system checkpoint;and do you have any idea at what point you want to recover your database? Even though they are in ACTIVE stauts, when you are taking backup. Still you can apply them how much you want. There will be no lost data. But ensure you haven't opened[resetologs] database.

RMAN hot backup requires archivelog all the time?

Hi all,
consider the case: a dml operation is running in oracle 11g database. after sometime it got completed and issued a commit statement. Now i took a full database hot backup using rman. but dint take archivelog backup(its must i know, but i want to know whether we can do incomplete recovery using only the full database backup and open database using RESETLOGS option?
Kindly let me know whether we can do incomplete recovery using only full database backup or we must need archivelog to open the database?
Regards,

Say your BACKUP DATABASE begins at 01:00am and finishes at 01:50am. At the minimum, you need to backup the Archivelogs from 01:00am to the first archivelolg after 01:50am. Technically you don't need the archivelogs of before 01:00am. However, if you want the ability to do a point in time recovery (which is a MUST for any production database), you would also backup the "earlier" archivelogs which can be used with the previous database backup.
Your commit does NOT guarantee that the database files are immediately updated -- DBWR "lazily" defers writing to the database files. Your commit is preserved in the online redo log. This has to be archived as an Archivelog and backed up.
Hemant K Chitale

Implementing Hot backup strategy

Hello everyone,
I am a newbie DBA and now working with an investment bank, their Oracle System is new and I am meant to to implement a backup startegy, the database is meant to be available 24/7, its oracle 9i on Windows Server 2003, it has got 25 tablespace and the data to be backed up is about 10GB.
I need advice on how to go about it, should I look into scripting or implement RMAN backup, because the backup has to be schduelled about midnight.
If scripting is the choose could someone advice because i don't know how to script.
Thanks in advance

If the data meant to be available for 24/7 , then you do not have any option , but to choose hot backups . Well I happene to be a great fan of RMAN and it's a great tool for backup and recovery purpose . As your database is not that big and it's only about 10 GB . you can consider hot backups through RMAN , as you want to backup it everyday , I would advise you to set retantion policy of 2 days.
rman > {
allocate channel device type disk ;
backup database ;
backup archivelog all delete input ;
hare krishna
Alok

Performance effect during HOT backup mode

Dear Experts,
Oracle 10gR2, Windows Server 2003 ,I.4TB database size
Our backup team put database in hot backup mode (alter tablespace begin......).
Is it cause some performance issue in the database ?
Thanks & Regards
Sunil Kumar

sunil kumar wrote:
Dear Aman,
As I told you I just joined and same thing I told to upper level, I need some definite proof so that I can prove my point because it always happens here: Database always put in hot backup mode and application here went very slow. I am a new DBA, so I need some some proof(what kind I don't know :)
Aman, hot backup with RMAN is more preferable as compare to alter tablespace begin backup...... command.
Why ?
and if so why we still using OS commands to take backup;
Thanks & Regards
Sunil Kumar
:)You have the answers to your other questions. As to "why we still using OS commands to take backup"? Well, um..... ;-) You'd have to ask you're organization that question. I can tell you there is no defensible reason to do so ..... ;-)

Hot backup cloning in ebs r12

HI i was doing the hot backup cloning in ebsr12.
i have backed up the control files and datafiles and the trace file also.
i have done the steps till copying the db and apps tier.
next is
2) Create the target database control file manually
Open the backed up control file
a. remove all lines before the startup nomount statement
b. Modify the REUSE to SET
c. Modify Source DB SID to Target SID (Here PROD to TEST)
d. Modify NORESETLOGS TO RESETLOGS
e. delete all lines after the CHARACTER SET statement
i am not sure about editing the control file ....
I am a started in db's
can anyone help me in this?

HI i was doing the hot backup cloning in ebsr12.
i have backed up the control files and datafiles and the trace file also.
i have done the steps till copying the db and apps tier.Looks like you are doing cold backup and not hot backup! Was the database cleanly shutdown before copying the database files?
a. remove all lines before the startup nomount statementCorrect -- Or you could leave those lines if they are commented.
b. Modify the REUSE to SETCorrect.
c. Modify Source DB SID to Target SID (Here PROD to TEST)Correct.
d. Modify NORESETLOGS TO RESETLOGSCorrect.
You will also have to change ARCHIVELOG to NOARCHIVELOG -- If your source instance is in ARCHIVELOG mode.
e. delete all lines after the CHARACTER SET statementKeep the lines/command that open the database and create the temporary tablespace.
Thanks,
Hussein

What are the consequences of not backing up controlfile in hot backup.

Hi All,
We have 8i,9i, 10g and 11g database. The unfortunate thing is that we are using this user managed hot backups for backing up our database. and I have no idea for what reason, we are not backing up the controlfile. Anyway, I would like you to comment on this, they said, they will recreate a text based controlfile and do the recover database until cancel using backup controlfile ; I know, if we have the path of all the datafiles , we can use this, but is this a right strategy ? of course, no one would agreed on this. I really appriciate, if somone could express his opinion in detail.
Regards

Hi,
The database consists of the following files:
Spfile/Pfile
Controlfile
Datafile
Redo Log
archivelog
When we talk about backing up the database, (no matter how) must take backup up of all these files.
If you are not taking these files in your backup you have a incomplete backup.
Why not take a back up of control file to a binary file. Is more simple and fast restore controlfile using binary file.
ALTER DATABASE BACKUP CONTROLFILE TO '/oracle/backup/control.bkp';To Trace should be used to produce SQL statements that can later be used to re-create your control file.
ALTER DATABASE BACKUP CONTROLFILE TO TRACE;Why not use RMAN? A resource with endless options and features.
Using user-managed backup you have none options/feature compared with the use of RMAN.
It can be used in all Oracle databases without additional license.
Regards,
Levi Pereira

Why archivelog mode is mandatory for hot backups.

Hi,
Why the database should be put in archivelog mode when we take hot backups. What happens actually. Why can't we put in noarchivelog mode and take hot backups?

Suppose you are not using RMAN then you must put your tablespaces in backup mode. Otherwise the backup you can take will be unrecoverable.
In order to recover from a Hot Backup you have to do followings
- Restore your Hot Backup
- Recover the database - here, the archive log files are important
How does Oracle know what has to be recovered from archivelogs?It looks at the SCN.
If you never put your tablespaces in backup mode then SCN would not be frozen and Oracle wouldn't know what has to be recovered.
Talip Hakan Ozturk
http://taliphakanozturken.wordpress.com/

Rman hot backup

hello
i am using rman hot backup script to take backup database everyday but the problem is it is working but not deleting old backup older than 2 days .
also i have question .. my database is in archive log mode and everyday about 6-7 .arch files generating in my archive directory.
it is not deleting the old files but generating new files everyday so adding up to the space.
SQL> show parameter archive
NAME TYPE VALUE
archive_lag_target integer 0
log_archive_config string
log_archive_dest string /u03/archive_logs/DEVL
log_archive_dest_1 string
also should i set dest_1 as archive location or just log_archive_dest
whats is the difference.?
my rman script is
RMAN Hot backup.unix script
The RMAN hot backup script rman_backup.sh:
# !/bin/bash
# Declare your environment variables
export ORACLE_SID=DEVL
export ORACLE_BASE=/u01/app/oracle
export ORACLE_HOME=/u01/app/oracle/product/11.2.0/db_1
export PATH=$PATH:${ORACLE_HOME}/bin
# Start the rman commands
rman target=/ << EOF
CONFIGURE CONTROLFILE AUTOBACKUP ON;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '/u03/backup/autobackup_control_file%F';
CONFIGURE RETENTION POLICY TO RECOVERY WINDOW OF 2 DAYS;
run {
allocate channel d1 type disk;
allocate channel d2 type disk;
allocate channel d3 type disk;
allocate channel d4 type disk;
ALLOCATE CHANNEL RMAN_BACK_CH01 TYPE DISK;
CROSSCHECK BACKUP;
BACKUP AS COMPRESSED BACKUPSET DATABASE FORMAT '/u03/backup/databasefiles_%d_%u_%s_%T';
sql 'ALTER SYSTEM ARCHIVE LOG CURRENT';
BACKUP AS COMPRESSED BACKUPSET ARCHIVELOG ALL FORMAT '/u03/backup/archivelogs_%d_%u_%s_%T' DELETE INPUT;
BACKUP AS COMPRESSED BACKUPSET CURRENT CONTROLFILE FORMAT '/u03/backup/controlfile_%d_%u_%s_%T';
CROSSCHECK BACKUP;
DELETE NOPROMPT OBSOLETE;
DELETE NOPROMPT EXPIRED BACKUP;
RELEASE CHANNEL RMAN_BACK_CH01;
EXIT;
EOF
thanks

Ahmer Mansoor wrote:
RMAN never deletes the Backups unless there is a space pressure in the Recovery Area. Instead it marks the Backups as OBSOLETE based on Retention Policy (in your case it is 2 Days),
To confirm it SET DB_RECOVERY_FILE_DEST_SIZE to some smaller value, the RMAN will remove all the Obsolete Backups automatically to reclaim space.Be very careful with this. If you generate a LOT of archivelog files and you exceed this size, on the next archivelog switch your database will hang with "cannot continue until archiver freed". RMAN will not automatically remove anything. RMAN only removes stuff when you program it in your script.
See:
http://docs.oracle.com/cd/E14072_01/backup.112/e10642/rcmconfb.htm#insertedID4 Retention Policy (recovery window or redundancy)
things like:
set retention window and number of copies
crosscheck backup
delete obsolete <-- delete old, redundant, no longer necessary backups/archivelogs
delete expired <-- NOTE: If you manually delete files and do not execute delete expired (missing file), the DB_RECOVERY_FILE_DEST_SIZE remains the same. So, you can clean out the space and oracle will still say the location is "full".
Understand that if you also set this parameter too small and your backup recovery window/redundancy are incorrectly set, you can also exhaust the "logical" space of this location again, putting your database at risk. Your parameter could be set to 100G on a 400G file system and even though you have 300G available, Oracle will see the limit of this parameter.
My suggestion, get in a DEV/TEST environment and test to see how to best configure your environment for RMAN database backups/control file, archivelog backups also taking into consideration OS tape backup solutions. I always configure DISK for RMAN backups, then have some other tape backup utility sweep those locations to tape ensuring that I have sufficient backups to reconstitute my database - I also include a copy of the init.ora file, password file as well as the spfile backup in this location.
>
In case of Archivelogs, It is better to create and execute a Purge Job to remove Archivelogs after backup them on tape.I almost agree. I try to keep all archivelogs necessary for recovery from last full backup online. I try to keep a full backup online as well. much faster at restoring stuff instead of trying to locate it on tape.

Why should not hot backup in rman

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