Encrypting RMAN backup

Configuring encryption for Oracle Recovery Manager (RMAN) is always a good step in the right direction. There may be different reasons for encrypting RMAN backup.

•  For greater security of data;
• Customer requirement (e.g, most companies requires encryption for any database file containing SSN, Credit Card number, date of birth, etc); or
• Complying with laws or regulations.

 
Option 1: Use global security wallet to encrypt backup

*configure the encryption wallet.

create a directory called "Wallet" in $ORACLE_BASE/admin/$ORACLE_SID

mkdir /home/oracle/app/oracle/admin/orcl/wallet

*Issue this command as SYS:

SQL> alter system set encryption key identified by "oracle1";

*Open the wallet:

SQL> alter system open encryption wallet identified by "oracle1";

*Log in to rman to encrypt backup

rman target /

RMAN> configure encryption for database on;

RMAN> backup database;


Option 2: Configure encryption right from RMAN

Another option is to configure encryption right from RMAN. You can also decide to use both options 1 and 2 together for double protection. Option one will be global because it controls every encryption done on the database including the backup. Option 2 is only restricted to RMAN prompt alone.

*Log in to RMAN and configure Encryption

RMAN target /

RMAN> set encryption on identified by "oracle1" only;

RMAN> backup database;

Note: You don't need a wallet to implement this. You can combine this with the global wallet transparent backup if you like. That will give you dual protection
You need to specify this password during recovery

  

Removing encryption

 

RMAN> configure encryption for database off;

Note: You need to set encryption off if at any point you don't need to encrypt your backup again. Some organizations will require you to remove encryption for data or databases that are only for TEST or DEVELOPMENT purpose.

Query encryption setting

Oracle provided a view to track encryption setting configured for recovery manager (RMAN). Issue this command as SYS:

select * from V$RMAN_ENCRYPTION_ALGORITHMS;

This is the view with all the details of rman encryption modes in the database. It is essential for a DBA to understand the encryption mode and their restrictions/limitations.

Thank you for reading.

RMAN-06169: could not read file header for datafile 7 error reason 9

Error
While attempting to run a backup of the database, we got an error identifying a problem with a datafile. In this post, I will discuss the cause of the problem and how the error was resolved.

rman target sys/****@PUBLIC

Starting backup at 01-APR-13
using channel ORA_DISK_1
RMAN-06169: could not read file header for datafile 7 error reason 9
RMAN-06169: could not read file header for datafile 7 error reason 9
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of backup plus archivelog command at 04/01/2013 15:54:32
RMAN-06056: could not access datafile 7

cause
There is a problem with the datafile 7. It could be due to corruption, or any other problem with the datafile. Oracle will not be able to back up the database except this datafile is restored. Alternative, as a temporary solution, you can skip the datafile in your backup. If the datafile is skipped, RMAN will be able to back up the database but it is not advisable.


solution:

Check the status of the datafile
sqlplus sys/***@PUBLIC

SQL> select file#, status from v$datafile where file# = 7;
FILE# STATUS
---------- -------
7 RECOVER

SQL> select file#, status, enabled from v$datafile where file# = 7;
FILE# STATUS ENABLED
---------- ------- ----------
7 RECOVER READ WRITE
exit;

Restore the datafile from backup
A copy of the datafile in backup can be used to restore the datafile. Simply log back into rman and issue this command:
RMAN> restore datafile 7;
datafile restored

NOTE: You do not need to put your database in mount mode to do this.

Recover the datafile
Recovering a datafile after restore brings it up to date. At this stage, archivelogs and incremental backups will be applied to bring the datafile to the point it was before the problem.

RMAN> recover datafile 7;
starting media recovery
database recovered


For more details on RMAN recovery and restore process, check out Oracle documentations at RMAN

common Oracle DBA interview questions and answer

Here is a small list of questions and answers for junior and mid-level Oracle DBA jobs. Mastery of these questions and answers will help you survive most interview session, and also expose you to some basic and advanced tips you need on the job.

What is the relationship between Control files and V$view?
V$views are kept in the control file. This is why v$ views are always accessible even when the database is in a lesser state.

Can you access V$view while the database is not open?
Yes. V$view can be accessed even when the database is in nomount mode or in a lesser state.

How many stages are involved in getting the database open and running?
3 stages namely: Nomount, Mount and Open stage

What are the Mandatory processes in Oracle?
The processes are the backgound processes. The mandatory ones are Checkpoint, PMON, SMON, Log Writer and Database Writer.

What is an instance?
A combination of memory structure and background processes.

Where can I monitor the Retore job that my colleague did to check if it went well or done properly?
Alert log. Alert log is in background dump. From SQL prompt issue: 'show parameter background dump'

I discovered that my control files are missing, what are my option?
Create another control file from the existing one (multiplex). If there is no existing one, create/build Control file from scratch with a text file. Always back up control file to Trace so that you can have a text file to create a fresh control file.

What is RAC?
Real Application Clusters. A combination of multiple instances accessing a database. The node represents each instance in the cluster.

Why should a client use RAC?
To avoid a single port failure. When there is only one instance, reliability and fault tolerance is low.

What are the demerits of RAC?
It is expensive to maintain. It requires lot of resources (hardware and manpower) as well as maintenance costs. Most firms now use VMware to reduce hardware costs.

What is ASM?
Automatic Storage Management

What would you use ASM?
It is free and more convenient for file management. It helps with load balancing as well as improves reliability and availability.

What is the difference between full and incremental backup?
Full backup is when you backup the whole database and the database is not in open mode. Incremental backup is when you copy the changes that has occured after the last full backup. This is usually done when the database is open and running, and in ARCHIVELOG mode.

Can you use RMAN without database in archivelog mode?
Yes, you can take a cold backup when the database is cleanly shut down.

What is DATAPUMP?
It is a new features that oracle introduced to enhance import and export of database, tablespace, schema and tables. Prior to Datapump, DBAs used regular imp and exp.

What are the basic features that differentiate Datapump from Import and Export?
Datapump allows remaping of database, tablespace, schema and tables. Datapump is also very fast. You can increase parallelism by increasing the workers that will execute the job.
Please note that parallelism is only compatible with Enterprise edition of oracle 10g and 11g.

Best of luck in your interviews and shoot me an email if you have questions.
Cheers!