Apply standby redo log to physical stby db.

Hi all,
Facing a problem in the following scenario.
I have dataguard configuration operating in maximum availability mode with a local standby db (A - lgwr sync not using real time apply) and a remote standby db (B - lgwr async). I then simualted a crash of my primary database with batch jobs running. Since the stby db A is in lgwr sync option ,all the commited data in the current online redo log has been transmitted to stby A and is present in its stby redo log (Group 2).How do I apply this stby redo log to the remote stby db.
Tried the following methods.
1.ftp the stby redo log to the remote db and tried to regiter it, got an error that it is not completely archived.
2.issued the recover standby database command and supplied the stby redo log when it asked for the sequence in the stby redo, got an error saying there is corruption in a block(tried this option multiple times ended up with the same result.)
Regards.

Hello,
Did you try "alter database recover managed standby database finish" on the standby database ?
Regards,
Shivananda

Similar Messages

Oracle DataGuard - Standy Redo log on physical Standby db

Hello Guys,
A quick question on my 10.2.0.2 db with Windows 2003 x64 OSs.
I have 2 machines - One for primary & the other for physical standby
I have successfully setup DG with Real Time Apply and also tested switchover & failover scenarios and they work well and as expected...
But I have a query which popped up when I was trying to set this up at home.
I create the physical standby db by shutting the primary db and copying all the datafiles, tempfiles,online redo logs and then creating a standby control file which will be used for the physical standby db to start off with.
After mounting the standby db, I tried to create standby redo logs files starting with Group 4 but I got error that standby group 4 already exists.
Upon querying v$logfile view, I noticed that the standby redo logs that I created on primary are also showing up on the standby db which I understand is from the standby control file.
So here is my quesiton: What is correct method of creating these standby redo logs on the standby database?
I know that I could drop those 4 standby redo logs from the standby db and recreate them but all the DG docs online and the documents that I have referred say that I should create the standby redo logs on the standby as I did on the primary but how can this duplication be avoided i.e. from the standby control file?
I know that I could use another method to create a hot backup such as RMAN etc...but I wanted to follow this way of shutting down the primary and copy the relevant database files.
Any help appreciated...and thanks in advance guys!
-Bharath

so with the setup that I used, i.e. create a standby control file which contains info about the standby redo logs at the primary site, should I also copy over the standby redo logs from the primary to standby as I only copied the datafiles, tempfile(s) & online redo logs? But then the filenames of the standby redo logs will be the exact same as that of the primary. Will that cause any issue during a switchover/failover?
I don't remember exactly how I did it when I got the whole thing working but I have a vague remembrance that I drop the std. redo log files entries from the std database and then recreate new ones with different filenames (as compared to primary).
Thanks

Physical standby database standby redo log problem

Hello
We have a physical standby database , I've created some standby redo log files but my problem is that they aren't used,
their status in v$stanby_log view is UNASSIGNED
and I see this message (ORA-16086: standby database does not contain available standby log files) in primary database alert_log file
while when I run "alter system switch logfile" in the primary database it transfer redo logs to the physsical standby database
and archive log file will be created in standby database
I've even recreated the standby redo log files and I added new ones to them but the problem wasn't solved
Do you know what is problem ?
elect group#,THREAD#,BYTES,STATUS from V$STANDBY_LOG;
group#     THREAD#      BYTES       STATUS
1                   0                   524288000                   UNASSIGNED
2                   0                   524288000                   UNASSIGNED
3                   0                   524288000                   UNASSIGNED
8                   0                   524288000                   UNASSIGNED
9                   0                   524288000                   UNASSIGNED
10                   0                   524288000                   UNASSIGNED
select group#,THREAD#,BYTES,MEMBERS,STATUS from v$log;
group#                    THREAD#                    BYTES                    MEMBERS                    STATUS
4                   1                   524288000                   2                   CLEARING
7                   1                   524288000                   2                   CLEARING_CURRENT
6                   1                   524288000                   2                   CLEARING
5                   1                   524288000                   2                   CLEARING
thanks

Hello Anurag
Thank you for your reply
I have found some issue in the standby database alert_log too , in the standby database alert_log it has been written:
RFS[782]: Assigned to RFS process 3919
RFS[782]: Identified database type as 'physical standby'
Primary database is in MAXIMUM AVAILABILITY mode
Standby controlfile consistent with primary
Primary database is in MAXIMUM AVAILABILITY mode
Standby controlfile consistent with primary
RFS[782]: No standby redo logfiles selected (reason:6)
Sun Jan 31 13:59:43 2010
Errors in file /u01/app/oracle/admin/tehrep/udump/tehrep_rfs_3919.trc:
ORA-16086: standby database does not contain available standby log files
Sun Jan 31 13:59:48 2010
RFS[781]: Archived Log: '/disks/sda/tehrep/archivelogs/1_6516_670414641.dbf'
Sun Jan 31 13:59:50 2010
and the context "/u01/app/oracle/admin/tehrep/udump/tehrep_rfs_3919.trc" is below :
+/u01/app/oracle/admin/tehrep/udump/tehrep_rfs_3919.trc+
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
ORACLE_HOME = /u01/app/oracle/product/10.2.0/db_1
System name:    Linux
Node name:      linserver2.com
Release:        2.6.9-42.ELsmp
Version:        #1 SMP Wed Jul 12 23:27:17 EDT 2006
Machine:        i686
Instance name: tehrep
Redo thread mounted by this instance: 1
Oracle process number: 58
Unix process pid: 3919, image: [email protected]
*** SERVICE NAME:() 2010-01-31 13:59:43.865
*** SESSION ID:(109.1225) 2010-01-31 13:59:43.865
KCRRFLAS
KCRRSNPS
No space in recovery area for active standby redo logs
The primary database is operating in MAXIMUM PROTECTION
or MAXIMUM AVAILABILITY mode, and the standby database
does not contain adequate disk space in the recovery area
to safely archive the contents of the standby redo logfiles.
ORA-16086: standby database does not contain available standby log files
when I saw this line "No space in recovery area for active standby redo logs" I thought that STANDBY_ARCHIVE_DEST parameter points where that there is no enough space , but when I consider I found out that points a directory on disk a "sda" that has enough space , I don't know what that means
by the way, at below I've written a section of the primary database alert_log context and "lgwr" trace file around Sun Jan 31 13:30:34 2010
alert_log :
ORA-16086: standby database does not contain available standby log files
Sun Jan 31 13:30:34 2010
LGWR: Failed to archive log 7 thread 1 sequence 6512 (16086)
Thread 1 advanced to log sequence 6512
Current log# 7 seq# 6512 mem# 0: /disks/sdb/tehrep/redo71.log
Current log# 7 seq# 6512 mem# 1: /disks/sdd/tehrep/redo72.log
LNSc started with pid=53, OS id=11451
Sun Jan 31 13:36:34 2010
Errors in file /u01/app/oracle/admin/tehrep/bdump/tehrep_lgwr_3692.trc:
ORA-16086: standby database does not contain available standby log files
Sun Jan 31 13:36:34 2010
LGWR: Failed to archive log 5 thread 1 sequence 6513 (16086)
Thread 1 advanced to log sequence 6513
Current log# 5 seq# 6513 mem# 0: /disks/sdb/tehrep/redo51.log
Current log# 5 seq# 6513 mem# 1: /disks/sdd/tehrep/redo52.log
*/u01/app/oracle/admin/tehrep/bdump/tehrep_lgwr_3692.trc file :*
Error 16086 creating standby archive log file at host '(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=tcp)(HOST=linserver2.com
+)(PORT=1521)))(CONNECT_DATA=(SERVICE_NAME=tehrep_XPT.com)(INSTANCE_NAME=tehrep)(SERVER=dedicated)))'+
*** 2010-01-31 13:30:34.712 60679 kcrr.c
LGWR: Attempting destination LOG_ARCHIVE_DEST_3 network reconnect (16086)
*** 2010-01-31 13:30:34.712 60679 kcrr.c
LGWR: Destination LOG_ARCHIVE_DEST_3 network reconnect abandoned
ORA-16086: standby database does not contain available standby log files
*** 2010-01-31 13:30:34.712 60679 kcrr.c
LGWR: Error 16086 creating archivelog file '(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=tcp)(HOST=linserver2.com)(PORT=1521
+)))(CONNECT_DATA=(SERVICE_NAME=tehrep_XPT.com)(INSTANCE_NAME=tehrep)(SERVER=dedicated)))'+
*** 2010-01-31 13:30:34.712 58941 kcrr.c
kcrrfail: dest:3 err:16086 force:0 blast:1
Receiving message from LNSc
*** 2010-01-31 13:30:34.718 55444 kcrr.c
Making upidhs request to LNSc (ocis 0x0xb648db48). Begin time is <01/31/2010 13:30:30> and NET_TIMEOUT <180> seconds
NetServer pid:11196
*** 2010-01-31 13:30:38.718 55616 kcrr.c
upidhs done status 0
*** 2010-01-31 13:36:31.062
LGWR: Archivelog for thread 1 sequence 6513 will NOT be compressed
*** 2010-01-31 13:36:31.062 53681 kcrr.c
+Initializing NetServer[LNSc] for dest=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=tcp)(HOST=linserver2.com)(PORT=1521)))(CO+
NNECT_DATA=(SERVICE_NAME=tehrep_XPT.com)(INSTANCE_NAME=tehrep)(SERVER=dedicated))) mode SYNC
LNSc is not running anymore.
New SYNC LNSc needs to be started
Waiting for subscriber count on LGWR-LNSc channel to go to zero
Subscriber count went to zero - time now is <01/31/2010 13:36:31>
Starting LNSc ...
Waiting for LNSc to initialize itself
*** 2010-01-31 13:36:34.116 53972 kcrr.c
+Netserver LNSc [pid 11451] for mode SYNC has been initialized+
Performing a channel reset to ignore previous responses
+Successfully started LNSc [pid 11451] for dest (DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=tcp)(HOST=linserver2.com)(PORT=1+
+521)))(CONNECT_DATA=(SERVICE_NAME=tehrep_XPT.com)(INSTANCE_NAME=tehrep)(SERVER=dedicated))) mode SYNC ocis=0x0xb648db48+
*** 2010-01-31 13:36:34.116 54475 kcrr.c
+Making upiahm request to LNSc [pid 11451]: Begin Time is <01/31/2010 13:36:31>. NET_TIMEOUT = <180> seconds+
Waiting for LNSc to respond to upiahm
*** 2010-01-31 13:36:34.266 54639 kcrr.c
upiahm connect done status is 0
Receiving message from LNSc
Receiving message from LNSc
Destination LOG_ARCHIVE_DEST_3 is in STANDBY RESYNCHRONIZATION mode
Receiving message from LNSc

The file structure online redo log, archived redo log and standby redo log

I have read some Oracle documentation for file structure and settings in Data Guard environment. But I still have some doubts. What is the best file structure or settings in Oracle 10.2.0.4 on UNIX for a data guard environment with 4 primary databases and 4 physical standby databases. Based on Oracle documents, there are 3 redo logs. They are: online redo logs, archived redo logs and standby redo logs. The basic settings are:
1. Online redo logs --- This redo log must be on Primary database and logical standby database. But it is not necessary to be on physical standby database because physical standby is not open. It doesn't generate redo log. However, if don't set up online redo log on physical standby, when primary failover and switch standby as primary. How can standby perform without online redo logs? In my standby databases, online redo logs have been set up.
2. Archived redo logs --- It is obviously that primary database, logical and physical standby database all need to have this log file being set up. Primary use it to archive log files and ship to standby. Standby use it to receive data from archived log and apply to database.
3. Standby redo logs --- In the document, it says A standby redo log is similar to an online redo log, except that a standby redo log is used to store redo data received from another database. A standby redo log is required if you want to implement: The maximum protection and maximum availability levels of data protection and Real-time apply as well as Cascaded destinations. So it seems that this standby redo log only should be set up on standby database, not on primary database. Am my understanding correct? Because I review current redo log settings on my environment, I have found that Standby redo log directory and files have been set up on both primary and standby databases. I would like to get more information and education from experts. What is the best setting or structure on primary and standby database?

FZheng:
Thanks for your input. It is clear that we need 3 type of redo logs on both databases. You answer my question.
But I have another one. In oracle ducument, it says If you have configured a standby redo log on one or more standby databases in the configuration, ensure the size of the current standby redo log file on each standby database exactly matches the size of the current online redo log file on the primary database. It says: At log switch time, if there are no available standby redo log files that match the size of the new current online redo log file on the primary database. The primary database will shut down
My current one data gurard envirnment setting is: On primary DB, online redo log group size is 512M and standby redo log group size is 500M. On the standby DB, online redo log group size is 500M and standby redo log group size is 750M.
This was setup by someone I don't know. Is this setting OK? or I should change Standby Redo Log on standby DB to 512M to exactly meatch with redo log size on primary?
Edited by: 853153 on Jun 22, 2011 9:42 AM

Standby Redo log creation

DB version: 11.2
OS : AIX 6.1
We have a 2 node RAC. We have one Disk group for all datafiles, tempfiles, redo logs,..etc.
Currenly in our primary DB, Redo logs look like
SQL> SELECT a.group#, b.thread#, a.member, b.bytes
FROM v$logfile a, v$log b WHERE a.group# = b.group#
order by a.group# , b.thread# 2    3 ;
         GROUP#         THREAD# MEMBER                                BYTES
              1               1 +ORCL_DG/orcl/orcl_log01.dbf         104857600
              2               1 +ORCL_DG/orcl/orcl_log02.dbf         104857600
              3               1 +ORCL_DG/orcl/orcl_log03.dbf         104857600
              4               2 +ORCL_DG/orcl/orcl_log04.dbf         104857600
              5               2 +ORCL_DG/orcl/orcl_log05.dbf         104857600
              6               2 +ORCL_DG/orcl/orcl_log06.dbf         104857600
6 rows selected.
1 member per group
3 group per instanceWe need to create a physical standby DB for the above DB with Real Time apply. For standby Redo logs, I need one extra log file for each Instance.
So, I am going to add
     group# 7 for thread 1
     and
     group# 8 for thread 2
Finally , SRLs will look like
         GROUP#         THREAD# MEMBER                                BYTES
              1               1 +ORCL_DG/orcl/orcl_log01.dbf         104857600
              2               1 +ORCL_DG/orcl/orcl_log02.dbf         104857600
              3               1 +ORCL_DG/orcl/orcl_log03.dbf         104857600
           7               1 +ORCL_DG/orcl/orcl_log07.dbf         104857600 -------> Additional
              4               2 +ORCL_DG/orcl/orcl_log04.dbf         104857600
              5               2 +ORCL_DG/orcl/orcl_log05.dbf         104857600
              6               2 +ORCL_DG/orcl/orcl_log06.dbf         104857600
           8               2 +ORCL_DG/orcl/orcl_log08.dbf         104857600 -------> AdditionalAnything wrong with my proposed SRL creation ?

JOE_humble wrote:
DB version: 11.2
OS : AIX 6.1
We have a 2 node RAC. We have one Disk group for all datafiles, tempfiles, redo logs,..etc.
Currenly in our primary DB, Redo logs look like
SQL> SELECT a.group#, b.thread#, a.member, b.bytes
FROM v$logfile a, v$log b WHERE a.group# = b.group#
order by a.group# , b.thread# 2    3 ;
GROUP#         THREAD# MEMBER                                BYTES
1               1 +ORCL_DG/orcl/orcl_log01.dbf         104857600
2               1 +ORCL_DG/orcl/orcl_log02.dbf         104857600
3               1 +ORCL_DG/orcl/orcl_log03.dbf         104857600
4               2 +ORCL_DG/orcl/orcl_log04.dbf         104857600
5               2 +ORCL_DG/orcl/orcl_log05.dbf         104857600
6               2 +ORCL_DG/orcl/orcl_log06.dbf         104857600
6 rows selected.
1 member per group
3 group per instanceWe need to create a physical standby DB for the above DB with Real Time apply. For standby Redo logs, I need one extra log file for each Instance.
So, I am going to add
     group# 7 for thread 1
     and
     group# 8 for thread 2
Finally , SRLs will look like
GROUP#         THREAD# MEMBER                                BYTES
1               1 +ORCL_DG/orcl/orcl_log01.dbf         104857600
2               1 +ORCL_DG/orcl/orcl_log02.dbf         104857600
3               1 +ORCL_DG/orcl/orcl_log03.dbf         104857600
           7               1 +ORCL_DG/orcl/orcl_log07.dbf         104857600 -------> Additional
4               2 +ORCL_DG/orcl/orcl_log04.dbf         104857600
5               2 +ORCL_DG/orcl/orcl_log05.dbf         104857600
6               2 +ORCL_DG/orcl/orcl_log06.dbf         104857600
           8               2 +ORCL_DG/orcl/orcl_log08.dbf         104857600 -------> AdditionalAnything wrong with my proposed SRL creation ?You have to create equal numbers & equal or greater size of standby redo log files than Online redo log files.
Refer http://www.pythian.com/news/581/oracle-standby-redo-logs/ to configure standby redo log files.

Standby redo log group for particular thread

hi masters,
actually i am performing an experiment to create physical standbyt database on the same machine as my primary database.
i ma going according to 'data guard admin guide'. while section for ading standby redo log group,it says that you have to add standby redo log group to "thread"....
what is this thread? and how can i foind to which thread i have to assign the next redo log group??
how can i find current thread??
what if i dont add "to thread' clause in my statement:-
ALTER DATABASE ADD STANDBY LOGFILE THREAD 5
2> ('/oracle/dbs/log1c.rdo','/oracle/dbs/log2c.rdo') SIZE 500M;
thanks and regards
VD

Vikrant,
First a question: Do you have a RAC instance? If so the paragraph even doesn't apply to you and I'm not sure why you are questioning it.
Secondly
"The THREAD clause is required only if you want to add one or more standby redo log
file groups to a specific primary database thread. If you do not include the THREAD
clause and the configuration uses Real Application Clusters (RAC), Data Guard will
automatically assign standby redo log file groups to threads at runtime as they are
needed by the various RAC instances."
this means you dont have to specify thread for RAC,as it will allocate one according to current thread.
Your conclusion is incorrect.
Where do you read the word 'current'?
Oracle will likely simply make sure each instance has sufficient standby redolog groups, the requirement is 1 standby redolog group per group + 1 extra.
Sybrand Bakker
Senior Oracle DBA

Standby Redo Log just sits as IN-MEMORY

Hi, I have shipped an archived redo log from my Primary to my physical standby.
I can see the log arriving at my Standby and being applied
select thread#, max(sequence#) "Last Standby Seq Received"
from v$archived_log val, v$database vdb
where val.resetlogs_change# = vdb.resetlogs_change#
group by thread# order by 1;
returns
   THREAD# Last Standby Seq Received
         1                       151
select thread#, max(sequence#) "Last Standby Seq Applied"
from v$archived_log val, v$database vdb
where val.resetlogs_change# = vdb.resetlogs_change#
and applied='YES'
group by thread# order by 1;
   THREAD# Last Standby Seq Applied
         1                      150
select stamp,name,applied
from v$archived_log
where applied != 'YES'
    STAMP
NAME
APPLIED
827498375
/home/app/oracle/fast_recovery_area/STANDBYL/archivelog/2013_09_30/o1_mf_1_151_9
4lrqpj3_.arc
IN-MEMORY
This log continually sits like this
I know that Redo Appply is active
select * from v$managed_standby where process = 'MRP0';
PROCESS          PID STATUS       CLIENT_P
CLIENT_PID
CLIENT_DBID
GROUP#                                   RESETLOG_ID    THREAD# SEQUENCE#
    BLOCK#     BLOCKS DELAY_MINS KNOWN_AGENTS ACTIVE_AGENTS
MRP0            3068 APPLYING_LOG N/A
N/A
N/A
N/A                                        820252586          1        152
      5038     102400          0            3             3
It looks as if 151 has been applied - yet
select thread#, max(sequence#) "Last Standby Seq Applied"
from v$archived_log val, v$database vdb
where val.resetlogs_change# = vdb.resetlogs_change#
and applied='YES'
group by thread# order by 1;
still shows 150 !
151 is not that big, I still would have expected it to have applied by now ( in excess of 30 mins )
Also I know there is no defer or time delay on the archive_destination setting on the Primary.
Any ideas why this standby redo log just sits IN-MEMORY ?
thanks,
Jim

Hello;
Not able to reproduce issue. Using Oracle 11.2.0.3 without Real-time apply.
select thread#, max(sequence#) "Last Standby Seq Received"
from v$archived_log val, v$database vdb
where val.resetlogs_change# = vdb.resetlogs_change#
group by thread# order by 1;
THREAD#                Last Standby Seq Received
1                      194
select thread#, max(sequence#) "Last Standby Seq Applied"
from v$archived_log val, v$database vdb
where val.resetlogs_change# = vdb.resetlogs_change#
and applied='YES'
group by thread# order by 1;
THREAD#                Last Standby Seq Applied
1                      194
select thread#, max(sequence#) "Last Standby Seq Applied"
from v$archived_log val, v$database vdb
where val.resetlogs_change# = vdb.resetlogs_change#
And Applied='YES'
group by thread# order by 1;
THREAD#                Last Standby Seq Applied
1                      194
SELECT ARCH.THREAD# "Thread", ARCH.SEQUENCE# "Last Sequence Received", APPL.SEQUENCE# "Last Sequence Applied"
FROM
(SELECT THREAD# ,SEQUENCE# FROM V$ARCHIVED_LOG WHERE (THREAD#,FIRST_TIME ) IN (SELECT THREAD#,MAX(FIRST_TIME) FROM V$ARCHIVED_LOG GROUP BY THREAD#)) ARCH,
(SELECT THREAD# ,SEQUENCE# FROM V$LOG_HISTORY WHERE (THREAD#,FIRST_TIME ) IN (SELECT THREAD#,MAX(FIRST_TIME) FROM V$LOG_HISTORY GROUP BY THREAD#)) APPL
WHERE
Arch.Thread# = Appl.Thread#
ORDER BY 1;
Thread                 Last Sequence Received Last Sequence Applied
1                      194                    194
select * from v$managed_standby where process = 'MRP0';
( shows the next sequence 195 on mine )
Is it possible the Standby has one extra archive? I've noticed that sometime you will see one extra on that side which appears to have nothing to do with the Data Guard process.
Best Regards
mseberg

Standby Redo Log Files ?

Hi Everyone,
Today after reading two different sources for Standby Protection Modes i found myself puzzled and stuck. One of the article from Burleson.com says 'Oracle supports the standby redo logs on a logical standby database and can now be configured in maximum data protection modes such as MAXIMUM PROTECTION ...'
On the other hand on some of the blogs and other resources to read, i found it something opposite to what Burleson Consulting posted on their website.
[http://4.bp.blogspot.com/-t0G_-xc8EAs/Tpvx9w2t8oI/AAAAAAAAAN4/Jw3U9s89Wtk/s1600/final.JPG|http://4.bp.blogspot.com/-t0G_-xc8EAs/Tpvx9w2t8oI/AAAAAAAAAN4/Jw3U9s89Wtk/s1600/final.JPG]
or
Blog from Jeff Hunter
[http://www.idevelopment.info/data/Oracle/DBA_tips/Data_Guard/DG_3.shtml|http://www.idevelopment.info/data/Oracle/DBA_tips/Data_Guard/DG_3.shtml]
Minimum Requirements for Data Protection Modes
     Maximum Protection      Maximum Availability      Maximum Performance
Redo Archival Process      LGWR      LGWR      LGWR or ARCH
Network Transmission Mode SYNC      SYNC      ASYNC when using LGWR process. Not applicable when using ARCH process.
Disk Write Option      AFFIRM      AFFIRM      NOAFFIRM
Standby Redo Logs Required?      Yes      Required for physical standby databases only (Standby redo logs are not supported for logical standby databases.)      Required for physical standby databases using the LGWR process.
Database Type      Physical only      Physical and Logical      Physical and Logical
Please help me to find true between the two.
Or please provide any doc to read.
Thanks
Prashant Dixit

Maximum Protection Maximum Availability Maximum PerformanceDepends on Business requirement, By default Performance[most of the clients]
Redo Archival Process ? ? ?LGWR recommended in Max performance
Network Transmission Mode ? ? ?Depends. If max performance asynchronous
Disk Write Option ? ? ?Not clear
Standby Redo Logs Required? ? ? ?If real time apply - YES
Database Type ? ? ?not clear,
Assuming physical or logical? --Depends on requirement , Preferably Physical.

Standby Redo Log Files and Directory Structure in Standby Site

Hi Guru's
I just want to confirm, i know that if the Directory structure is different i need to mention these 2 parameter in pfile
on primary site:
DB_CONVERT_DATAFILE='standby','primary'
LOG_CONVERT_DATAFILE='standby','primary'
On secondary Site:
DB_CONVERT_DATAFILE='primary','standby'
LOG_CONVERT_DATAFILE='primary','standby'
But i want to confirm this wheather i need to issue the complete path of the directory in both the above paramtere:
like:
DB_CONVERT_DATAFILE='/u01/oracle/app/oracle/oradata/standby','/u01/oracle/app/oracle/oradata/primary'
LOG_CONVERT_DATAFILE='/u01/oracle/app/oracle/oradata/standby','/u01/oracle/app/oracle/oradata/primary'
Second Confusion:-
After transferring Redo Standby log files created on primary and taken to standby on the above mentioned directory structure and after restoring the backup of primary db alongwith the standby control file will not impact the physical standby redo log placed on the above mentioned location.
Thanks in advance for your help

Hello,
Regarding your 1st question, you need to provide the complete path and not just the directory name.
On the standby:
db_file_name_convert='<Full path of the datafiles on primary server>','<full path of the datafiles to be stored on the standby server>';
log_file_name_convert='<Full path of the redo logfiles on primary server>','<full path of the redo logfiles on the standby server>';
Second Confusion:-
After transferring Redo Standby log files created on primary and taken to standby on the above mentioned directory structure and after restoring the backup of primary db alongwith the standby control file will not impact the physical standby redo log placed on the above mentioned location.
How are you creating the standby database ? Using RMAN duplicate or through the restore/recovery options ?
You can create the standby redo logs later.
Regards,
Shivananda

Where RFS exactly write redo data ? ( archived redo log or standby redo log ) ?

Good Morning to all ;
I am getting bit confused from oracle official link . REF_LINK : Log Apply Services
Redo data transmitted from the primary database is received by the RFS on the standby system ,
where the RFS process writes the redo data to either archived redo log files or standby redo log files.
In standby site , does rfs write redo data in any one file or both ?
Thanks in advance ..

Hi GTS,
GTS (DBA) wrote:
Primary & standby log file size should be same - this is okay.
1) what are trying to disclose about largest & smallest here ? - You are confusing.
Read: http://docs.oracle.com/cd/E11882_01/server.112/e25608/log_transport.htm#SBYDB4752
"Each standby redo log file must be at least as large as the largest redo log file in the redo log of the redo source database. For administrative ease, Oracle recommends that all redo log files in the redo log at the redo source database and the standby redo log at a redo transport destination be of the same size."
GTS (DBA) wrote:
2) what abt group members ? should be same as primary or need to add some members additionally. ?
Data Guard best practice for performance, is to create one member per each group in standby DB. on standby DB, one member per group is reasonable enough. why? to avoid write penalty; writing to more than one log files at the standby DB.
SCENARIO 1: if in your source primary DB you have 2 log member per group, in standby DB you can have 1 member per group, additionally create an extra group.
primary
standby
Member per group
2
1
Number of log group
4
5
SCENARIO 2: you can also have this scenario 2 but i will not encourage it
primary
standby
Member per group
2
2
Number of log group
4
5
GTS (DBA) wrote:
All standby redo logs of the correct size have not yet been archived.
- at this situation , can we force on standby site ? any possibilities ?
you can not force it , just size your standby redo files correctly and make sure you don not have network failure that will cause redo gap.
hope there is clarity now
Tobi

Standby redo log

In what situation, standby redo logs are mandatory.
I have the below settings and my DATA GAURD setup (10.2.0.3) is working fine without Stdby redo logs.
Just wondering when do i need standby redo logs.
SQL> show parameter log_Archive_dest_2
NAME TYPE VALUE
log_archive_dest_2 string SERVICE=TO_STANDBY LGWR ASYNC
AFFIRM DB_UNIQUE_NAME=stand
SQL> select protection_mode from v$database;
PROTECTION_MODE
MAXIMUM PERFORMANCE

888442 wrote:
In what situation, standby redo logs are mandatory.
I have the below settings and my DATA GAURD setup (10.2.0.3) is working fine without Stdby redo logs.
Just wondering when do i need standby redo logs.
SQL> show parameter log_Archive_dest_2
NAME TYPE VALUE
log_archive_dest_2 string SERVICE=TO_STANDBY LGWR ASYNC AFFIRM DB_UNIQUE_NAME=stand
SQL> select protection_mode from v$database;
PROTECTION_MODE
MAXIMUM PERFORMANCEHi,
Standby Redo Logs (SRL) require when you are using MAX AVAILABILITY and MAX PROTECTIN protection modes. So SRL using for Real Time Apply.
In your case (Max Performance) if you want real time apply on standby you must add SRLs to standby database.
Best practice we adding standby redo logs to primary and standby database same time, but when database role is standby then using SRLs.
You can ask, why also to primary? Because we can switchover to standby, then priamry role will change to standby, then will use SRLs.
Regards
Mahir M. Quluzade

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

Online redo logs vs standby redo logs

Hi All,
Oracle version : 10.2.0.4
OS : SunOS 5.10 Generic_118855-36 i86pc i386 i86pc
This might be a silly question for the experts :(
We are having 2 standby databases and 1 logical database. Everything is running fine , I have one confusion : My primary server having 3 online redo log files and 3 standby redo log files (on primary local), but as per the architecture standby redo logs should be on standby server.My question is whether standby redo logs on standby are online redo logs of standby server or standby redo logs of primary server. e.g If i perform a log switch on primary then what is the role of sync and affirm, will lgwr write parallel on online redo logs ,standby redo logs (of primary) or online redo logs (of primary) and online redo logs (which is known as standby redo logs on standby ). Please help me to understand the scenerio.
Thanks in advance!

RFS receives redo information from the primary database.
RFS can write the redo into standby redo logs or directly to archived redo logs. Each LNSn and ARCn process from the primary database has its own RFS process.
A standby redo log is used only when the database is in the standby role to store redo data received from the primary database. Standby redo logs form a separate pool of log file groups.
Configuring standby redo log files is highly recommended on all standby databases in a Data Guard configuration, including the primary database to aid in role reversal.
A standby redo log is required to implement:
• The maximum protection and maximum availability levels of data protection
• Real-time apply
• Cascaded redo log destinations
Standby redo logs are recommended for maximum performance data protection mode. Unless you are using the real-time apply feature, standby redo logs must be archived before the data can be applied to the standby database. The standby archival operation occurs automatically.

Apply standby redo log to physical stby db.

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