Multiplexing control file

How to multiplexing control file in oracle 10g?

Hi,
Two ways are to MULTIPLEXING CONTROL FILE.
If you are using PFILE..
1. Set a Parameter... CONTROL_FILE= <ORACLE_BASE>\ORADATA\ORCL\CONTROL1.CTL,<ORACLE_BASE>\ORADATA\ORCL\CONTROL2.CTL
If you are using SPFILE..
2. Then use, ALTER SYSTEM CLAUSE to change the paremeter value dynamically.
for ex> ALTER SYSTEM SET CONTROL_FILE=<ORACLE_BASE>\ORADATA\ORCL\CONTROL1.CTL, <ORACLE_BASE>\ORADATA\ORCL\CONTROL2.CTL
Thanks.

Similar Messages

  • How to multiplexing control files in ASM instance???

    Hi Folks
    I have an Oracle DB10g R2 with ASM in which the unique control file is in one group of ASM.
    My question is how to multiplex the controlfile and redo logs???
    Very thanks,
    Wilson

    Hi, you can use the OMF feature of ORACLE to move the controlfile into the ASM.
    1. you create a backup controlfile: ALTER DATABASE BACKUP CONTROLFILE TO '/home/oracle/control.bac';
    2. you specify the locations:
    - ALTER SYSTEM SET db_create_online_log_dest_1='+ASMGROUP1'; -- RMAN will restore one mirror of the controlfile in each of these locations!
    - ALTER SYSTEM SET db_create_online_log_dest_2='+ASMGROUP1';
    ALTER SYSTEM SET db_recover_file_dest='+ASMGROUP1'; -- this will make RMAN restore the controlfile in the flash_recovery_area!
    3. you create a pfile from spfile:
    - CREATE PFILE FROM SPFILE;
    4. you archive the current redolog:
    - ALTERSYSTEM ARCHIVE LOG ALL;
    and SHUTDOWN IMMEDIATE
    5. you edit the pfile by removing the entry for CONTROL_FILES!!!
    - and after this: CREATE SPFILE FROM PFILE;
    6. you use RMAN to restore the controlfile in the ASM:
    RMAN> STARTUP NOMOUNT;
    RMAN> RESTORE CONTROLFILE FROM '/home/oracle/control.bac';
    RMAN> ALTER DATABASE MOUNT;
    RMAN> RECOVER DATABASE USING BACKUP CONTROLFILE;
    RMAN>ALTER DATABASE OPEN RESETLOGS;
    Hope this helps,
    Lutz

  • Multiplex control files in Oracle 10g...

    Hi ,
    the Oracle documentation , in one of its books points out....:
    'Once the disk drive is repaired, the damaged control file can be restored using the intact copy of the control file from the other disk and the instance can be restarted'.
    Is it achievable automatically.... or using some kind of sql commands and which , if any.....?????
    Regards,
    Simon

    there's a parameter called
    control_files
    in your spfile/pfile whichever you use.
    You can just multiply as many control files as you wish at OS level (copy) and list them in the parameter, then start your database.

  • Creating a Control File

    I have a question about creating another control file. If I want to create another control file, do I need to put the values/paths of the current control files in the CREATE CONTROLFILE statement?

    996403 wrote:
    If I am wanting to create a new control file, do you recommend:
    1. Use the Create Control file statementWhen to Create New Control Files:
    All control files for the database have been permanently damaged/missing and you do not have a control file backup.
    You want to change one of the permanent database parameter settings originally specified in the CREATE DATABASE statement.
    These settings include the database name and the following parameters: MAXLOGFILES, MAXLOGMEMBERS, MAXLOGHISTORY, MAXDATAFILES, and MAXINSTANCES.
    For example, you would change a database name if it conflicted with another database name in a distributed environment,
    or you would change the value of MAXLOGFILES if the original setting is too low.
    2. Copy an existing control file and then edit the parameter file?i will recommend 2nd (if you have healthy control file) if you want multiplex control files.

  • How to make the control file consistent when I re-mulitplexing them

    Oracle 10g R2 on the AIX 5.3L
    My current control files (three) from the default set-up are all located in the same directory (/dbbaan/oradata/<SID>/). If I want to change some of the multiplexing of the control file to different directory to avoid the media failure,
    1. I copy one or two control files to different directory.
    2. create a new init_sid.ora from spfile
    2. edit the init_sid.ora file and change the locations of the control file
    3. shutdown/restart the DB using the init_sid.ora.
    4. create the spfile from the pfile
    5 shutdown/restart the DB with new spfile ( "SQL> startup")
    My question is: since there is always time lag between copying and recreating the new init_sid.ora, while the control file(s) are constantly updating, how can Db guarrente the consistency of the DB when I restart the DB (the control file specified in the init_sid.ora may be some time old) ? or does it matter?
    I did above and my DB restart without problem.

    Another problem concerns me. What happen if one of
    multiplexed control file location, which I use a NFS
    of another server, goes down and is not available
    during the operation ( After I restart up the DB)? I
    am sure I will see the error of that control file in
    the alert log.If one of the control files not accessible during operation, Oracle will crash. So you better make sure all of your control file location are reliable and accessible.

  • How many control files will be present in a database?

    How many control files will be present in a database?

    See this link for control file recommendations
    http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96524/c04space.htm
    See the portion "Control Files Overview" and the last "Multiplexed Control Files"
    Don't forget to reward points if this answer your query.

  • ORA-01207: file is more recent than control file - old control file

    Hi,
    Today while i am multiplexing control files, i am getting error
    ORA-01207: file is more recent than control file - old control file
    Action taken:
    a) shutdown the db
    b) make changes in the control file by replacing all control files with a single good one control file
    c) startup nomount pfile
    d) create spfile from pfile
    e) startup the database
    But getting the below errors:
    ORA-01122: database file 1 failed verification check
    ORA- 01110: data file 1:
    ORA - 01207: file is more recent than control file - old control file
    Can anyone help on same
    Regards
    Vikas Kohli

    Vikas Kohli wrote:
    Hi,
    Today while i am multiplexing control files, i am getting error
    ORA-01207: file is more recent than control file - old control file
    Action taken:
    a) shutdown the db
    b) make changes in the control file by replacing all control files with a single good one control file
    c) startup nomount pfile
    d) create spfile from pfile
    e) startup the database
    But getting the below errors:
    ORA-01122: database file 1 failed verification check
    ORA- 01110: data file 1:
    ORA - 01207: file is more recent than control file - old control file
    Can anyone help on same
    Regards
    Vikas Kohli
    Please read the following MOS ID: Starting Database Returns ORA-01122, ORA-0110, and ORA-01207 (Doc ID 1011193.6)

  • Losing 2 control files

    I'm reading this document about multiplexing control files: http://docs.oracle.com/cd/E11882_01/server.112/e25494/control002.htm#i1006192
    But couldn't it happen to lose even 2 of the 3 control files ?
    What are the steps when I lose two of them ?

    Hello,
    controlfile should be multiplexd on different locations. If you lost for example 2 of 3, then you can recover from the last one you have. If you lost all controlfiles, then you should have a good backup and restore it from there.
    regards
    Peter

  • How to mulitplex control files with raid

    I have installed 8i DB server on a HP proliant server machine. Raid 2 is configured on the server machine with windows OS, two hard disks are mirrored.
    It is often recommended to multiplex conrol files and redo log files on multiple hard disk to protect from disk failure.
    how can i do this, as i have 3 logical drives but all they are of same physical device.
    multiplexing control files on different logican drives is same as keeping them in the same default folder.
    Please help making things clear ?????

    1. RAID is all about availability and is not a substitute for duplexing of control files or online redo logs.
    2. It is better to have multiple physical drive (sets) on which to place copies of the control file and online redo logs. That way, any failure of the RAID or file system will still leave you with copies of these vital files.
    3. If you only have logical drives, it is best to place copies on various logical volumes. This way, you are (at least) protected from file system failure, corruption, or accidental delete.

  • What is Control file ?

    Hi Gurus,
    Please explain me that what is Control file and what was the purpose of it in SAP Oracle DataBase.
    Thanks.

    Hi Kalyan
    <b>What Is a Control File?</b>
    Every Oracle Database has a control file, which is a small binary file that records the physical structure of the database. The control file includes:
    The database name
    Names and locations of associated datafiles and redo log files
    The timestamp of the database creation
    The current log sequence number
    Checkpoint information
    The control file must be available for writing by the Oracle Database server whenever the database is open. Without the control file, the database cannot be mounted and recovery is difficult.
    The control file of an Oracle Database is created at the same time as the database. By default, at least one copy of the control file is created during database creation. On some operating systems the default is to create multiple copies. You should create two or more copies of the control file during database creation. You can also create control files later, if you lose control files or want to change particular settings in the control files.
    <b>Guidelines for Control Files</b>
    This describes guidelines you can use to manage the control files for a database, and contains the following topics:
    Provide Filenames for the Control Files
    Multiplex Control Files on Different Disks
    Back Up Control Files
    Manage the Size of Control Files
    Role of Control File will remain the same even when you use Oracle with SAP. Just there will be some more entries in the file.
    Refer the link below as well:
    http://download-east.oracle.com/docs/cd/B19306_01/server.102/b14231/control.htm#i1006143
    Hope this should clear you doubt.
    Regards
      Sumit Jain
    [Reward with points if useful]
    Message was edited by:
            Sumit Jain

  • Multiplex Redo Logs and Control File

    I am wanting to setup an existing Oracle Express 10g instance to multiplex the redo log files and the control file.
    Instance is using Oracle-Managed Files and the Flash Recovery Area.
    With these options being used what are the steps required to setup multiplexing?
    I tried setting the DB_CREATE_ONLINE_LOG_DEST_1 and DB_CREATE_ONLINE_LOG_DEST_2 parameters but this doesn't appear to have worked (I even bounced the db instance).
    BTW, the DB_CREATE_FILE_DEST is set to null and the DB_RECOVERY_FILE_DEST is set to the flash recovery area.
    Any help is much appreciated.
    Regards, Sheila

    Thanks for this. My instance originally had two log groups so I've added a new member to each group into the same flash recovery area directory, but have assigned a name. Is this why when I query v$logfile the is_recovery_dest_file is set to NO? Is it ok to assign a name & directory and if not, how do you add a new memeber and allow Oracle-Managed files to name them?
    Also, how can I check that the multiplexing is working (ie the database is writing to both sets of files)?
    Thanks again.

  • Multiplexing redo logs and control files to a separate diskgroup

    General question this one...
    I've been using ASM for a few years now and have always installed a new system with 3 diskgroups
    +DATA - for datafiles, control files, redo logs
    +FRA - for achive logs, flash recovery. RMAN backup
    Those I guess are the standards, but I've always created an extra (very small) diskgroup, called +ONLINE where I keep multiplexed copies of the redo logs and control files.
    My reasoning behind this is that if there are any issues with the +DATA diskgroup, the redo logs and control files can still be accessed.
    In the olden days (all those 5 years ago!), on local storage, this was important, but is it still important now? With all the striping and mirroring going on (both at ASM and RAID level), am I just being overtly paranoid? Does this additional +ONLINE diskgroup actually hamper performance? (with dual write overheads that are not necessary)
    Thoughts?

    Some of the decision will probably depend on your specific environment's data activity, volume, and throughput.
    Something to remember is that redo logs are sequential write, which benefit from a lower RAID overhead (RAID-10, 2 writes per IOP vs RAID-5, 4 writes per IOP). RAID-10 is often not cost-effective for the data portion of a database. If your database is OLTP with a high volume of random reads/writes, you're potentially hurting redo throughput by creating contention on the disks sharing data and redo. Again, that depends entirely on what you're seeing in terms of wait events. A low volume database would probably not experience any noticeable degraded performance.
    In my environment, I have RAID-5 and RAID-10 available, and since the RAID-10 requirement from a capacity perspective for redo is very low, it makes sense to create 2 diskgroups for online redo, separate from DATA, and separate from each other. This way, we don't need to be concerned with DATA transactions impacting REDO performance, and vice versa, and we still maintain redo redundancy.
    In my opinion, you can't be too paranoid. :)
    Good luck!
    K

  • Multiplexing Online redo logs, archive logs, and control files.

    Currently I am only multiplexing my control files and online redo logs, My archive logs are only going to the FRA and then being backed up to tape.
    We have to replace disks that hold the FRA data. HP says there is a chance we will have to rebuild the FRA.
    As my archive logs are going to the FRA now, can I multiplex them to another disk group? And if all of the control files, online redo logs and archive logs are multiplexed to another disk group, when ASM dismounts the FRA disk group due to insufficient number of disks, will the database remain open and on line.
    If so then I will just need to rebuild the ASM volumes, and the FRA disk group and bring it to the mount state, correct?
    Thanks!

    You can save your online redo logs and archive logs anywhere you want by making use of of init params create_online_log_dest and log_archive_dest_n. You will have to create new redo log groups in the new location and drop the ones in the FRA. The archive logs will simply land wherever you designate with log_archive_dest_n parameters. Moving the control files off FRA is a little trickier because you will need to restore your controlfile to a non-FRA destination and then shutdown your instance, edit the control file param to reflect changes and restart.
    I think you will be happier if you move everything off the FRA diskgroup before dismounting it, and not expecting the db to automagically recover from the loss of files on the FRA.

  • Control file multiplexed RAID question

    2 node RAC. OEL 5. 11.2.0.2
    Is there any cause for concern over design issues when placing multiplexed controlfiles on disks with different RAID types?
    I have FRA, REDO, VOTE and DATA disk groups available to me DATA is RAID 5, the rest are RAID 10. Is there any tales from the field of write speed issues multiplexing the files on a RAID 5 and a RAID 10?
    Edited by: 961469 on Dec 11, 2012 6:10 AM
    edited to include versions and env

    Is there any cause for concern over design issues when placing multiplexed controlfiles on disks with different RAID types?IMHO, I believe not. Of course this depend on characteristic of I/O of each Array.
    As best practice never mix files stored on array with heavy I/O with array which has Low I/O.
    Controlfile is good for RAID 5 and RAID 10 no worry.
    Read note:
    I/O Tuning with Different RAID Configurations [ID 30286.1]
    Swap space can be used on RAID devices without affecting Oracle.  
    ====================================================================================
    RAID  Type of RAID        Control       Database        Redo Log        Archive Log
                                File          File            File            File
    ====================================================================================
    0     Striping             Avoid          OK           Avoid           Avoid    
    1     Shadowing             OK             OK          Recommended       Recommended
    0+1   Striping +            OK         Recommended       OK            Avoid    
          Shadowing                                                                                 
    3     Striping with         OK           Avoid           Avoid            Avoid    
          Static Parity                                                                                        
    5     Striping with         OK           Avoid           Avoid            Avoid    
          Rotating Parity                  
    ------------------------------------------------------------------------------------On this case the main concern is:
    Something which should help can disrupt and cause downtime.
    Unable To Open Database Due To Diskgroup Used To Multiplex The RedoLogs & Controlfiles & Archivelogs Got Corrupted. [ID 1382372.1]
    Regards,
    Levi Pereira

  • Functioning of control file when re-created

    Hi friends,
    we can recover database without data loss when there is a situation to re-create control file(for suppose control file is lost and no multiplexed copies are available) using NORESETLOGS option in controlfile script.
    when we re-create controlfile, no SCN and checkpoint information will be there in controlfile. Then how controlfile will get the latest SCN and how it allows DB to be up and running.
    please explain. thanks in advance

    Hi,
    As per my knowledge I am explaning what will happen at Background.
    As you said that control File is lost and no mutiplexed, In that scenario you are going to recreate the Controlfile. As we know that control file will be in Sync with All DataFiles (System etc.,) , which will hold the SCN numbers, When the Instance is UP with the newly Created ControlFile (Since scn is not available), it will get the Highest SCN Number from Current DataFiles and Check for in Sync with other Datafiles, whether SCN is in Sync with the Other data files or not.
    And further proceed with Recovery Process Based on the Redo Logs.
    As you said if the required SCN is not available in the Redo Logs it will Check for the Archive Redo Logs Based on the SCN i.e., (If Req SCN is < SCN in Redo Logs) It will Check for Archive Logs files.
    Let me know in case If I am not clear or some where wrong in concept so that I can learn some thing inturn from others.!!
    Thanks & Regards,
    Pavan Kumar N

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