Urgent: Database recovery
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  1. #1
    Join Date
    Jan 2000
    Posts
    387

    Unhappy

    Hi,

    I am testing out database recovery by exporting a full dump file of the database while the database is still open (hot backup) and using the dump file to copy into another machine to make sure that all the files are available and the database is working fine.

    When I tried to startup the database, I got the following errors:

    ora-01122: database file 17 failed verification check
    ora-01110: database file 17 '/app/oracle......./archive.dbf'
    ora-01207:file is more recent than controlfile - old controlfile

    Question1: Is it because i did a hot backup and whenever there is a write, the controlfile sequence will change, which is why the file is more recent than controlfile?

    Question 2: How do i solve this error? What could be the cause of them?

    Later, I did a 'recover database using controlfile until cancel' and I did an 'alter database open resetlogs', then I have encountered another set of errors:

    ora-01194: file 1 needs more recovery to be consistent
    ora-01110: '/app/oracle...../system01.dbf'

    Question 3: How do i overcome this set of errors?

    Question 4: Is there any proper ways of recovering from hot backup?

    Thank you so much for sharing Pls help!


  2. #2
    Join Date
    Jan 2001
    Posts
    126
    Hi,

    Did you use the consistent option during the export as your database was in use?

    Baliga

  3. #3
    Join Date
    Feb 2001
    Posts
    389
    In Active database, even if you take a hot backup and restore, restore with archive logs and the latest controlfile,(get controlfile using alter database backup controlfile as '.....'. and then let oracle do recovery, if it gives errors, then run manual recovery.

    The problem here is, u did not get the controlfile after the hot backup.
    U do recover database using backup controlfile, only when u loase the controlfiles and u have the recent backup.


    Right noe , u have lost everything, restore everything from backup.

  4. #4
    Join Date
    Jun 2000
    Location
    Chennai/India
    Posts
    90
    Hi,
    first you will have to use consistent=Y during the export 'cause there are some system objects which will get exported and later this will lead to inconsistency.
    A Winner never Quits, A Quitter never Wins
    Ganesh .R

  5. #5
    Join Date
    Feb 2001
    Posts
    44
    Hi,

    You need to recover more datafiles.
    I have also encountered this situation.
    Connect to server manager and then connect internal.
    You should use 'alter database recover datafile
    as specified by the system.
    Then again restart the machine.If you require more files to recover the system will tell you the names of those datafiles.
    Hope this helps
    bye

  6. #6
    Join Date
    Nov 2000
    Posts
    212
    there is one old article on metalink:
    Note:3286.1 V6 Recovery - How It Works and Some Examples
    It explains quite a lot, regadles of V6 of Oracle.

    Disclaimer: what is said bellow could be wrong :-)
    To question 1
    ora-01207:file is more recent than controlfile - old controlfile

    Looks like you tried to recover database with OLD control file. In that case you need to specify

    recover [until cancel, etc] using backup controlfile

    That 'backup controlfile' clause is only needed to allow database to pass sequence numbers recorded in control file.

    To error:
    ora-01194: file 1 needs more recovery to be consistent
    ora-01110: '/app/oracle...../system01.dbf'

    When I get this error while doing a recovery using "recover [until cancel, etc] using backup controlfile", the solution is to apply latest online redo log.
    Then recover gives message "media recovery completed" and database opens with reset logs.
    However I am amazed why it is that way, as all datafiles seems to be checkpointed at the same SCN before applying that latest online redo log.



  7. #7
    Join Date
    Jan 2000
    Posts
    387
    Hi,

    Thanks for sharing your experiences. I am trying to do a recovery using physical backup (tape backup), however i have encountered the controlfile errors which is caused by the write to database duing the backup. In this case, how am i going to recover from physical backup without encountering the controlfile errors? Do i use 'alter database backup controlfile to trace' command and with this i can restore the control files using the physical backup too?

    In the second case is that during an export, will it export controlfiles too? Is that why consistent=Y must be stated?

    I need more help in this topic... Thanks everyone!






  8. #8
    Join Date
    Jun 2000
    Location
    Madrid, Spain
    Posts
    7,448
    Well I dont know what did you do.
    To start with EXPORT is NOT a hot backup, it is a logical backup

    When you say you start up the database, whcih database are we talking about here the new one or the old one which you exported?

    Consistent has nothing to do with your situation, it is used to avoid inconsistent data when you export when there DML going

  9. #9
    Join Date
    Nov 2000
    Posts
    212
    if you have recent control file, then it should not be a problem just to 'recover database [until cancel]' I suppose.
    By the way, how you perform hot backup, via RMAN or alter tablespace begin/end backup and OS utility to copy files?

  10. #10
    Join Date
    Jun 2000
    Location
    Madrid, Spain
    Posts
    7,448
    if you do NOT have any control files or the trace like control file, create it manually! Then use

    recover database using backup controlfile until cancel

    With this option Oracle doesnt know when to stop so you will have to be careful here, very. Nevertheless i would backup the existing database just in case you have to apply recovery again if your first attempt fails

    But anyway I dont see how the heck an EXPORT would lead you to this situation

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