Oracle disaster recovery using Backup Exec

Before recovery:

1. full closed backup

Do not use shutdown abort to forcibly shut down the shutdown database), implement a file-level backup, back up all Oracle related files, including Windows system files, system status and Oracle program files and data files.

This cold backup is critical for quick recovery of the Oracle database system. Without it, the system can only be reinstalled and restored after it is damaged, which is much slower and more complex than direct recovery of cold backup.

This cold backup should be re-created whenever the physical or logical structure of the database or form changes.

2. full online backup

This Backup should be completed through Backup Exec Agent for Oracle Server. to back up all tablespaces, archive logs and control files, Oracle will write all the cached content to the file after Backup, archive the online redo log, so the database backup contains the real-time information of the database during backup, which is complete and effective. You can restore the status of the last full online backup later.

Recovery Process:

1. reinstall Windows and Remote Agent for Windows Server to prepare the environment for restoring the Oracle Server.

2. Restore the last full closed backup and restart the computer.

In Windows, the Oracle database system is complete, but the Oracle database may not be the latest data. Backup Exec Agent for Oracle Server does not need to be re-installed.

3. Use SQLPlus to connect to the database system as sysdba and close the database.
Shutdown immediate + <enter>

4. Use the Media Server to Restore the latest full online backup. Make sure that the "Restore over Existing files overwrite Existing files" option is selected in the advanced options for restoring job properties.

To recover the database successfully, all redo logs after the last full closed backup must have been archived and backed up. If the database is missing, the database cannot be restored to the status of the last full onli ne backup.

The alert log of Oracle shows the archive logs required for database recovery and where you should restore them.

5. After the restoration is complete, use the SYS user to connect to the database as sysdba and load the database to the mount stage:
Startup mount + <enter>

6. After the database is mounted, perform the recover process:
Recover database using backup controlfile + <enter>

The database prompts you which logs are required:

ORA-00279: Change 36579 generatedNeeded for thread 1
ORA-00289: Suggestion: \ Oracle_Home \ Oradata \ \ % SID % T00036579.ARC
ORA-00280 :{ = Suggested | filename | AUTO | FROM logsource | CANCEL}

The simplest method is to select automatic recovery:
Auto + <enter>

The system will. search for all required logs in the location defined in the ora file and apply them in sequence. The last log to be applied is the online redo log. In fact, it does not include any transaction, but only one SCN, you can skip this step, but the automatic recovery process reports an error because the corresponding file cannot be found:

ORA-00308: cannot open archived log
'E: \ ORACLE \ ORADATA \ KIMSTAD \ ARCHIVE \ kimstadt00042549.arc'
ORA-27041: unable to open file
OSD-04002: unable to open file
O/S-Error: (OS 2) The system cannot find the file specified.

Enter the following command until cancel to abort the recovery process as needed ):
Recover database until cancel using backup controlfile +

In this way, we can stop the restoration process when the previous error is prompted again in the last stage of database recovery:
Cancel + <enter>

In this case, all the commit transactions except the last online redo log have been submitted to the database. After the operation is completed, the following information is displayed:
Media recovery canceled

In fact, the recovery process has been completed normally.

Finally, open the database and synchronize the log serial number:
Alter database open resetlogs + <enter>

So far, the Oracle database is successfully restored to the last Full Online backup.

Note:Oracle 8i can use the internal account to perform DBA operations. 9i canceled the internal account, and the SYS account replaced it. To Log On as a dba, The nolog parameter should be added when SQL Plus is started. Then, log on again, connect username/password as sysdba.