Oracle control file backup recovery noresetlogs recovery

Backup of control files can be performed in two formats: Text backup and binary backup.

Backup text format

SQL> alterdatabase backup controlfile to trace as '/bk/con. SQL ';

 

Databasealtered.

Backup binary format

SQL> alterdatabase backup controlfile to trace as '/bk/con. ctl ';

 

Databasealtered.

---- Add the as clause to customize the storage location

SQL>! Cp/etc/passwd/u01/tiger/oradata/orcl2/control01.ctl

 

SQL> altersystem swirch logfile;

Alter systemswirch logfile

*

ERROR at line 1:

ORA-02065: illegal options for ALTER SYSTEM

 

 

SQL> altersystem switch logfile;

Alter systemswitch logfile

*

ERROR at line 1:

ORA-03113: end-of-file on communication channel

SQL> conn/assysdba

Connected to anidle instance.

SQL> startup

Oracle instancestarted.

 

Total SystemGlobal Area 314572800 bytes

Fixed Size 1219136 bytes

VariableSize 109053376 bytes

DatabaseBuffers 197132288 bytes

RedoBuffers 7168000 bytes

ORA-00205: errorin identifying control file, check alert log for more info

We can find that there is a problem with the control file during the mount operation, so that we can restore the control file based on the text file of the control file backed up earlier.

Createcontrolfile reuse database "ORCL2" NORESETLOGS ARCHIVELOG

MAXLOGFILES 16

MAXLOGMEMBERS 3

MAXDATAFILES 100

MAXINSTANCES 8

# MAXLOGHISTORY 292

LOGFILE

GROUP 1'/u01/tiger/oradata/orcl2/redo01.log' SIZE 50 M,

GROUP 2'/u01/tiger/oradata/orcl2/redo02.log 'SIZE 50 M,

GROUP 3 '/u01/tiger/oradata/orcl2/redo03.log' SIZE50M

DATAFILE

'/U01/tiger/oradata/orcl2/system01.dbf ',

'/U01/tiger/oradata/orcl2/tiger. dbf ',

'/U01/tiger/oradata/orcl2/sysaux01.dbf ',

'/U01/tiger/oradata/orcl2/users01.dbf ',

'/U01/tiger/oradata/orcl2/undotbs02.dbf ',

'/U01/tiger/oradata/orcl2/undotbs01 ',

'/U01/tiger/oradata/orcl2/tiger01.dbf'

CHARACTER SETZHS16GBK

SQL> alterdatabase open;

Alter databaseopen

*

ERROR at line 1:

ORA-01113: file1 needs media recovery

ORA-01110: datafile 1: '/u01/tiger/oradata/orcl2/system01.dbf'

SQL> recoverdatabase;

Media recoverycomplete.

SQL> alterdatabase open;

Databasealtered.