Data Guard - Redo log files

Hi....
I have done data guard .......every thing is fine.......archives are bring transferred to standby..........
Also, during configuration, I had created standby redolog groups 4,5,6 and copied to standby.....
But in real time apply.......the standby is not using standby redolog groups 4,5,6........when i am query v$log it is showing group 1,2,3.
Actually, its should use standby redo log for maximum availability.
Please help....
Thanks in advance.

There was a similar question here just a few days ago:
Data Guard - redo log files

Similar Messages

Require 9i Primary and Standby redo logs files same size?

Hi,
We have 9.2.0.6 Oracle RAC (2 node) and configured data guard (physical standby).
I want to increase redo log files size, but i can't this do same time primary and standby side.
Is there a rule, primary and standby database instances have same size redo log files?
If I increase only primary redo log files, is there any side effect? However I try this issue on test system. I increased all primary redo log files(if status='INACTIVE' drop redo log group and add redo log group, switch logfile,...)
, but i couldn't changed standby side. So the system is work well. Is this correct solution or not? How can i increase both sides redo log files?
Thank you for helps..

Thank you for your helps.. I found this issue answer:
http://download-west.oracle.com/docs/cd/B19306_01/server.102/b14239/manage_ps.htm#i1010448
Consequently, when you add or drop an online redo log file at the primary site, it is important that you synchronize the changes in the standby database by following these steps:
If Redo Apply is running, you must cancel Redo Apply before you can change the log files.
If the STANDBY_FILE_MANAGEMENT initialization parameter is set to AUTO, change the value to MANUAL.
Add or drop an online redo log file:
To add an online redo log file, use a SQL statement such as this:
SQL> ALTER DATABASE ADD LOGFILE '/disk1/oracle/oradata/payroll/prmy3.log' SIZE 100M;
To drop an online redo log file, use a SQL statement such as this:
SQL> ALTER DATABASE DROP LOGFILE '/disk1/oracle/oradata/payroll/prmy3.log';
Repeat the statement you used in Step 3 on each standby database.
Restore the STANDBY_FILE_MANAGEMENT initialization parameter and the Redo Apply options to their original states.
bye..

Standby redo log file

Hi,
From oracle document i know in the standby side the RFS process writes to Standby redo log file -> archive log and the MRP procees applys the archive logs to the standby database.
my question is ,if we dont create standby redo log file what happens?

Hello;
When redo is received by an RFS on the standby , the RFS process writes the redo data into archived redo logs or optionally to the SRL.
Standby Redo Logs is where the RFS process at your Standby database writes incoming redo, they help performance because the RFS does not have to create the Archive log file.
Standby redo logs are a component of the Data Guard setup. They should be the same size as the redo logs on the Primary.
Standby Redo Logs do not not to be multiplexed.
I would create SRL them on both the Primary and the Standby. Think of it as one database in either Standby or Primary Mode. If you have to switchover you still need them.
If you have SRL's setup and need to do either a failover or switchover it should occur faster and safer.
Best Regards
mseberg

What is the purpose of standby redo log files

Hi,
What is the purpose of the standby redo log files in DR?
what if the standby redo log files are created? or else not created?
Please explain
Thanks

3.1.3 Configure a Standby Redo LogA standby redo log is required for the maximum protection and maximum availability modes and the LGWR ASYNC transport mode is recommended for all databases. Data Guard can recover and apply more redo data from a standby redo log than from archived redo log files alone.
You should plan the standby redo log configuration and create all required log groups and group members when you create the standby database. For increased availability, consider multiplexing the standby redo log files, similar to the way that online redo log files are multiplexed.>
Reference http://download.oracle.com/docs/cd/B19306_01/server.102/b14239/create_ps.htm#i1225703
HTH
Anand

Dataguard lost both Primary redo log and standby redo log files

Hi,
I am new to data guard, i came acorss a scenario where we loose both primary redo log file and standby redo log files.
Can someone please help me understand how to recover from this situation.
Thanks!

>loose both primary redo log file and standby redo log files
We have to be very clear.
There are (set A) online redo log files and (set B) standby redo log files at (location 1) Primary and (location 2) Standby.
The standby redo log files, depending on the configuration, aren't strictly mandatory. The standby can be applying redo without online redo log files present as well, depending on how it was setup.
So, the question is : Did you lose online redo log files at the primary ? Didn't the primary shutdown itself then ? If so, you have to do an incomplete recovery at the primary OR switch over to the standby (which may or may not have received the last transaction, depending on how it was configured and operating) OR restore from the standby (again, with possible loss of transactions) to the primary.
Hemant K Chitale

Use of standby redo log files in primary database

Hi All,
What is the exact use of setting up standby redo log files in the primary database on a data guard setup?
any good documents?

A standby redo log is required for the maximum protection and maximum availability modes and the LGWR ASYNC transport mode is recommended for all databases. Data Guard can recover and apply more redo data from a standby redo log than from archived redo log files alone.
You should plan the standby redo log configuration and create all required log groups and group members when you create the standby database. For increased availability, consider multiplexing the standby redo log files, similar to the way that online redo log files are multiplexed.
refer the link,and Perform the following steps to configure the standby redo log.:-
http://download.oracle.com/docs/cd/B19306_01/server.102/b14239/create_ps.htm#i1225703
If the real-time apply feature is enabled, log apply services can apply redo data as it is received, without waiting for the current standby redo log file to be archived. This results in faster switchover and failover times because the standby redo log files have been applied already to the standby database by the time the failover or switchover begins.
refer the link
http://download.oracle.com/docs/cd/B19306_01/server.102/b14239/log_apply.htm#i1023371

How to disable write to redo log file in oracle7.3.4

in oracle 8, alter table no logged in redo log file like: alter table tablename nologging;
how to do this in oracle 7.3.4?
thanks.

user652965 wrote:
Thanks very much for your help guys. I appreciate it. unfortunately none of these commands worked for me. I kept getting error on clearing logs that redo log is needed to perform recovery so it can't be cleared. So I ended up restoring from earlier snapshot of my db volume. Database is now open.
Thanks again for your input.And now, as a follow-up, at a minimum you should make sure that all redo log groups have at least 3 members. Then, if you lose a single redo log file, all you have to do is shutdown the db and copy one of the good members (of the same group as the lost member) over the lost member.
And as an additional follow-up, if you value your data you will run in archivelog mode and take regular backups of the database and archivelogs. If you fail to do this you are saying that your data is not worth saving.

Problem in creating database -Missing Redo log file

I am try to create a new database using DBCA .While creating a database it shows the error oracle instance terminated.Force Disconnected.
My alert log file is
Errors in file /u01/app/oracle/diag/rdbms/oracl/oracl/trace/oracl_ora_5424.trc:
ORA-00313: open failed for members of log group 1 of thread 1
ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/oracl/redo01.log'
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
Wed Nov 06 10:07:27 2013
Errors in file /u01/app/oracle/diag/rdbms/oracl/oracl/trace/oracl_ora_5424.trc:
ORA-00313: open failed for members of log group 2 of thread 1
ORA-00312: online log 2 thread 1: '/u01/app/oracle/oradata/oracl/redo02.log'
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
Errors in file /u01/app/oracle/diag/rdbms/oracl/oracl/trace/oracl_ora_5424.trc:
ORA-00313: open failed for members of log group 3 of thread 1
ORA-00312: online log 3 thread 1: '/u01/app/oracle/oradata/oracl/redo03.log'
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
Wed Nov 06 10:07:38 2013
Setting recovery target incarnation to 2
Wed Nov 06 10:07:38 2013
Assigning activation ID 1876274518 (0x6fd5ad56)
Thread 1 opened at log sequence 1
Current log# 1 seq# 1 mem# 0: /u01/app/oracle/oradata/oracl/redo01.log
Successful open of redo thread 1
Wed Nov 06 10:07:38 2013
MTTR advisory is disabled because FAST_START_MTTR_TARGET is not set
Wed Nov 06 10:07:38 2013
SMON: enabling cache recovery
Errors in file /u01/app/oracle/diag/rdbms/oracl/oracl/trace/oracl_ora_5424.trc (incident=1345):
ORA-00600: internal error code, arguments: [kpotcgah-7], [12534], [ORA-12534: TNS:operation not supported
Incident details in: /u01/app/oracle/diag/rdbms/oracl/oracl/incident/incdir_1345/oracl_ora_5424_i1345.trc
Wed Nov 06 10:07:46 2013
Trace dumping is performing id=[cdmp_20131106100746]
Errors in file /u01/app/oracle/diag/rdbms/oracl/oracl/trace/oracl_ora_5424.trc:
ORA-00600: internal error code, arguments: [kpotcgah-7], [12534], [ORA-12534: TNS:operation not supported
Error 600 happened during db open, shutting down database
USER (ospid: 5424): terminating the instance due to error 600
Instance terminated by USER, pid = 5424
ORA-1092 signalled during: alter database "oracl" open resetlogs...
ORA-1092 : opiodr aborting process unknown ospid (5424_47935551851664)
Wed Nov 06 10:07:47 2013
ORA-1092 : opitsk aborting process
251,1 95%

>I am try to create a new database using DBCA
>Please help me to resolve this issue.My redo log file was missing
DROP and recreate the database. It is a *new* database without any data.
Check what datafile locations and redo log file locations you specify when creating the new database. Check if you have permissions and enough disk space.
Hemant K Chitale

How to remove a redo log file

Hi Experts,
I want to remove a wrong redo log file from 10G R2 database in window.
how to do that without loss data?
my steps as
1. alter system switch logfile;
2. select * from v$log;
which ARC and sataus do I can drop redo log file based on above SQL
no archive and active status?
ALso Which account should I do above action?
fExamp, system account added redo log file, i only
can drop by system? how about sys?
Thanks help in detail steps
Jim
Edited by: user589812 on Dec 23, 2008 4:35 PM

Jim,
Check this link out for how to drop a redo log file
Make sure a redo log group is archived (if archiving is enabled) before dropping it. To see whether this has happened, use the V$LOG view.
http://download.oracle.com/docs/cd/B19306_01/server.102/b14231/onlineredo.htm#i1006489
SELECT GROUP#, ARCHIVED, STATUS FROM V$LOG;
   GROUP# ARC STATUS
        1 YES ACTIVE
        2 NO CURRENT
        3 YES INACTIVE
        4 YES INACTIVE
Drop a redo log group with the SQL statement ALTER DATABASE with the DROP LOGFILE clause.
The following statement drops redo log group number 3:
ALTER DATABASE DROP LOGFILE GROUP 3;

Restore in noarchivelog mode ( redo log files have been dropped )

1, A full backup taken using RMAN is available on disk.
2, The current control files were NOT damaged and do not need to be restored.
3, All data files are damaged .
4, The database is in NOARCHIVELOG mode.
I restore database :
1. RMAN> STARTUP MOUNT
2. RMAN> RESTORE DATABASE;
3. RMAN> recover database;
in this step , I got the information about needing redo log files ; but the redo log
files have been dropped , what should i do ?
else
I want to know there is the command 'recover database using backup control file'
in rman or not ?
Tks

Possibly loss of data (because information in online redo logs is lost):
recover database until cancel;
(cancel immediately)
alter database open resetlogs; (to build a new set of redo logs)
It's not necessary to use a backup controlfile here.

How to recover from one corrupted redo log file in NOARCHIVE mode?

Oracle 10.2.1.
The redo log file was corrupted and Oracle can't work.
When I use STARTUP mount, I got no error msg.
SQL> startup mount
ORACLE instance started.
Total System Global Area 1652555776 bytes
Fixed Size 1251680 bytes
Variable Size 301991584 bytes
Database Buffers 1342177280 bytes
Redo Buffers 7135232 bytes
Database mounted.
But I have some applications which are depended on Oracle can't be started.
So, I tried STARTUP open. But I got error msg.
SQL> startup open
ORACLE instance started.
Total System Global Area 1652555776 bytes
Fixed Size 1251680 bytes
Variable Size 301991584 bytes
Database Buffers 1342177280 bytes
Redo Buffers 7135232 bytes
Database mounted.
ORA-00368: checksum error in redo log block
ORA-00353: log corruption near block 497019 change 42069302 time 11/07/2007
23:43:09
ORA-00312: online log 4 thread 1:
'G:\ORACLE\PRODUCT\10.2.0\ORADATA\NMDATA\REDO04.LOG'
So, how can I restore and recover my database?
If use RMAN, how to do that?
Any help will be appreciated.
Thanks.

Hi, Yingkuan,
Thanks for the helps.
Actually, I have 10 redo log files exists. All of them are here.
I tried your suggestion:
alter database clear unarchived logfile group 4;
The error msg I got is the same as before:
SQL> alter database clear unarchived logfile group 4;
alter database clear unarchived logfile group 4
ERROR at line 1:
ORA-01624: log 4 needed for crash recovery of instance nmdata (thread 1)
ORA-00312: online log 4 thread 1:
'G:\ORACLE\PRODUCT\10.2.0\ORADATA\NMDATA\REDO04.LOG'
Compared to losing all the data, it is OK for me lose some of them.
I have more than 1 TB data stored and 99.9% of them are raster images.
The loading of these data were the headache. If I can save them, I can bear the lost.
I want to grasp the last straw.
But I don't know how set the parameter: allowresetlogs_corruption
I got the error msg:
SQL> set allowresetlogs_corruption=true;
SP2-0735: unknown SET option beginning "_allow_res..."
I have run the command:
Recover database until cancel
Alter database open resetlogs
The error msg I got is the following:
SQL> recover database until cancel
ORA-00279: change 41902930 generated at 11/05/2007 22:01:48 needed for thread 1
ORA-00289: suggestion :
D:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\NMDATA\ARCHIVELOG\2007_11_09\O1_MF_
1_1274_%U_.ARC
ORA-00280: change 41902930 for thread 1 is in sequence #1274
Specify log: {<RET>=suggested | filename | AUTO | CANCEL}
cancel
ORA-01547: warning: RECOVER succeeded but OPEN RESETLOGS would get error below
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: 'D:\ORACLE\PRODUCT\10.2.0\ORADATA\NMDATA\SYSTEM01.DBF'
ORA-01112: media recovery not started
SQL>
From the log file, I got the following:
ALTER DATABASE RECOVER database until cancel
Fri Nov 09 00:12:48 2007
Media Recovery Start
parallel recovery started with 2 processes
ORA-279 signalled during: ALTER DATABASE RECOVER database until cancel ...
Fri Nov 09 00:13:20 2007
ALTER DATABASE RECOVER CANCEL
Fri Nov 09 00:13:21 2007
ORA-1547 signalled during: ALTER DATABASE RECOVER CANCEL ...
Fri Nov 09 00:13:21 2007
ALTER DATABASE RECOVER CANCEL
ORA-1112 signalled during: ALTER DATABASE RECOVER CANCEL ...
Thank you very much. and I am looking forward to your followup input.

Hoping for a quick response : EXP and Archived REDO log files

I apologize in advance if this question has been asked and answered 100 times. I admit I didn't search, I don't have time. I'm leaving on vacation tomorrow, and I need to know if I'm correct about something to do with backup / restore.
we have 10g R2 running a single instance on a single server. The application vendor has "embedded" oracle with their application. The vendor's backup is a batch file using EXP - thus:
exp system/xpwdxx@db full=y file=D:\Orant\admin\db\EXP\db_full.dmp log=D:\Orant\admin\db\EXP\db_full.txt direct=y compress=y
This command is executed nightly at midnight. The files are then backed up by our nightly backup to offsite storage media.
Te database is running in autoarchive mode. The problem is, the archived redo files filled the drive they were being stored on, and it is the drive the database is on. I used OS commands to move 136G of archived redo logs onto other storage media to free the drive.
My question: Since the EXP runs at midnight, when there is likely NO activity, do I need to run in AutoArchive Mode? From what I have read, you cannot even apply archived redo log files to this type of backup strategy (IMP) Is that true? We are ok losing changes since our last EXP. I have read a lot of stuff about restoring consistent vs. inconsistent, and just need to know: If my disk fails, and I have to start with a clean install of Oracle and nothing else, can I IMP this EXP and get back up and running as of the last EXP? Or do I need the autoarchived redo log files back to July 2009 (136G of them).
Hoping for a quick response
Best Regards, and thanks in advance
Bruce Davis

Bruce Davis wrote:
Amardeep Sidhu
Thank you for your quick reply. I am reading in the other responses that since I am using EXP without consistent=y, I might not even have a backup. The application vendor said that with this dmp file they can restore us to the most recent backup. I don't really care for this strategy as it is untested. I asked them to verify that they could restore us and they said they tested the dmp file and it was OK.
Thank you for taking the time to reply.
Best Regards
BruceThe dump file is probably ok in the sense it is not corrupted and can be used in an imp operation. That doesn't mean the data in it is transactionally consistent. And to use it at all, you have to have a database up and running. If the database is physically corrupted, you'll have to rebuild a new database from scratch before you can even think about using your dmp file.
Vendors never understand databases. I once had a vendor tell me that Oracle's performance would be intolerable if there were more than 5 concurrent connections. Well, maybe in HIS product ..... Discussions terminated quickly after he made that statement.

How to increase the size of Redo log files?

Hi All,
I have 10g R2 RAC on RHEL. As of now, i have 3 redo log files of 50MB size. i have used redo log size advisor by setting fast_start_mttr_target=1800 to check the optimal size of the redologs, it is showing 400MB. Now, i want to increase the size of redo log files. how to increase it?
If we are supposed to do it on production, how to do?
I found the following in one of the article....
"The size of the redo log files can influence performance, because the behavior of the database writer and archiver processes depend on the redo log sizes. Generally, larger redo log files provide better performance, however it must balanced out with the expected recovery time.Undersized log files increase checkpoint activity and increase CPU usage."
I did not understand the the point however it must balanced out with the expected recovery time in the above given paragraph.
Can anybody help me?
Thanks,
Praveen.

You dont have to shutdown the database before dropping redo log group but make sure you have atleast two other redo log groups. Also note that you cannot drop active redo log group.
Here is nice link,
http://www.idevelopment.info/data/Oracle/DBA_tips/Database_Administration/DBA_34.shtml
And make sure you test this in test database first. Production should be touched only after you are really comfortable with this procedure.

Online redo log files being removed physically

Grid Infra version: 11.2.0.4
RDBMS Version: 11.2.0.4
Although this is a RAC DB, this is not a RAC-specific question. Hence posting it here.
Few months back, I remember issuing a command similair to below (DROP LOGFILE GROUP ...) and the redo log files were still physically present in the diskgroup.
If I remember correctly, the file is not deleted physical so that we can use the REUSE functionality (ALTER DATABASE ADD LOGFILE MEMBER '+REDO/orcl/onlinelog/redo1b.log' reuse to group 11; ) ie. you can use the REUSE command to add the logfile of the same name which is physically present in OS Filesystem/Diksgroup to redo log group.
But today, after I issued the below command, I checked the diskgroup location from ASMCMD
SQL> alter database drop logfile group 31;
Database altered.
From ASMCMD, I can that the file has disappeared physically. Is this a new feature with 11.2.0.4 or am I missing something here ?
ASMCMD> ls +DATA/msblprd/onlinelog/group_31.548.833154995
ASMCMD-8002: entry 'group_31.548.833154995' does not exist in directory '+DATA/msblprd/onlinelog/'

Just to add to what Aman has said.
It is a bad practice not to let OMF decide the placement of Online redo logs because of this issue especially when you use ASM.
Executing rm command in Linux/Unix is easy but Dropping ASM aliases in the disk group can be a hassle.
This is documented.
"When a redo log member is dropped from the database, the operating system file is not deleted from disk. Rather, the control files of the associated database are updated to drop the member from the database structure. After dropping a redo log file, ensure that the drop completed successfully, and then use the appropriate operating system command to delete the dropped redo log file."
http://docs.oracle.com/cd/E11882_01/server.112/e25494/onlineredo.htm#ADMIN11324
BTW . You don't even need to set db_create_online_log_dest_n to enable OMF for ORLs.
SQL> show parameter log_dest
NAME                                 TYPE        VALUE
db_create_online_log_dest_1          string
db_create_online_log_dest_2          string
db_create_online_log_dest_3          string
db_create_online_log_dest_4          string
db_create_online_log_dest_5          string
SQL> show parameter db_create_file_dest
NAME                                 TYPE        VALUE
db_create_file_dest                  string      +MBL_DATA
alter database add logfile thread 4
group 31 ('+MBL_DATA','+MBL_FRA') size 4096M,
group 32 ('+MBL_DATA','+MBL_FRA') size 4096M,
group 33 ('+MBL_DATA','+MBL_FRA') size 4096M,
group 34 ('+MBL_DATA','+MBL_FRA') size 4096M ;
Database altered.
And redo logs will be neatly placed as shown below
   INST     GROUP# MEMBER                                             STATUS           ARC
         4         31 +MBL_DATA/bsblprd/onlinelog/group_31.276.832605441 UNUSED           YES
                      +MBL_FRA/bsblprd/onlinelog/group_31.297.832605445 UNUSED           YES
                   32 +MBL_DATA/bsblprd/onlinelog/group_32.547.832605451 UNUSED           YES
                      +MBL_FRA/bsblprd/onlinelog/group_32.372.832605457 UNUSED           YES
                   33 +MBL_DATA/bsblprd/onlinelog/group_33.548.832605463 UNUSED           YES
                      +MBL_FRA/bsblprd/onlinelog/group_33.284.832605469 UNUSED           YES
                   34 +MBL_DATA/bsblprd/onlinelog/group_34.549.832605475 UNUSED           YES
                      +MBL_FRA/bsblprd/onlinelog/group_34.359.832605481 UNUSED           YES

Unassigned Status Of Standby Redo Log Files

I created 2 standby redo log groups, and use LGWR in primary site to
transfer redo data, all are good. But when I query the V$STANDBY_LOG
view, I found that the status column of my both standby redo logs is UNASSIGNED".
also sequence#
THREAD# and all others are 0 and 0.
Any explains.

Thanks for the reply Sophie. I did perform log switch at my primary site but the status of standby redo log files remained unassinged. I am pasting here the message in my Alert Log file may be that can help you to diagonose the problem.
ALTER DATABASE SET STANDBY DATABASE PROTECTED
Tue Jul 26 15:35:18 2005
Completed: ALTER DATABASE SET STANDBY DATABASE PROTECTED
Tue Jul 26 15:35:22 2005
ALTER DATABASE OPEN
Tue Jul 26 15:35:23 2005
LGWR: Primary database is in CLUSTER CONSISTENT mode
LGWR: Primary database is in MAXIMUM PROTECTION mode
LGWR: Destination LOG_ARCHIVE_DEST_1 is not serviced by LGWR
LNS0 started with pid=18
Tue Jul 26 15:35:28 2005
LGWR: Error 16086 verifying archivelog destination LOG_ARCHIVE_DEST_2
LGWR: Continuing...
Tue Jul 26 15:35:28 2005
Errors in file e:\oracle\admin\test\bdump\test_lgwr_1864.trc:
ORA-16086: standby database does not contain available standby log files
LGWR: Error 16086 disconnecting from destination LOG_ARCHIVE_DEST_2 standby host 'TESTstdb'
LGWR: Minimum of 1 applicable standby database required
Tue Jul 26 15:35:28 2005
Errors in file e:\oracle\admin\test\bdump\test_lgwr_1864.trc:
ORA-16072: a minimum of one standby database destination is required
LGWR: terminating instance due to error 16072
Instance terminated by LGWR, pid = 1864

Data Guard - Redo log files

Similar Messages

Maybe you are looking for