Tales From A Lazy Fat DBA

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Background Processes – Revisited

Posted by FatDBA on November 18, 2012

SMON
The System Monitor carries out a crash recovery when a crashed instance is started up again. It also cleans temporary segments. SMON checks the SCN in all datafile headers when the database is started. Everything is OK if all of these SCNs matches the SCN found in the controlfile. If the SCNs don’t match, the database is in an inconsistent state. SCN Number is the System Change Number provided by Oracle for each committed transaction. When the database in inconsistent state while the database is opened, crash recovery is done. Crash recovery is the recovery of a database in a single-instance configuration or an Oracle Real Application Clusters configuration in which all instances have crashed. In contrast, instance recovery is the recovery of one failed instance by a live instance in an Oracle Real Application Clusters configuration. SMON wakes up every 5 minutes to perform housekeeping activities. SMON must always be running for an instance. If not, the instance will terminate.

SMON_SCN_TIME is the metadata table populated for every five minutes by SMON, If column_tracking_level is set to 1 SMON also updates sys.col_usage$ another metadata table.

PMON
The Process Monitor checks if a user process fails and if so, do all cleaning up of resources that the user process has acquired. In the case of shared server configuration, PMON checks dispatchers and server processes and restarts them if they have failed. It also does another important thing. During service registration, PMON provides the listener with Names of the database services provided by the database. However, if there is no listener at startup, PMON can obviously not register those information. Therefore, PMON tries then periodically to register with the listener, which might take up to 60 seconds. During service registration it provides listener with the following information:

– Name of the associated instance
– Current load and maximum load on instance
– Names of DB services provided by database.
– Information about dedicated servers and dispatchers (depends on database server mode i.e dedicated/shared server mode)

PMON process wakes up at every 60 seconds and provide information to the listener. If any problem arises and your PMON process fails then it’s not possible to register information to listener periodically. In this case you can do ‘Manual service registration’ using command:

ALTER SYSTEM REGISTER;

This command forces the registration of database information to the listener.

MMAN (Memory Manager) is a background process that manages the dynamic resizing of SGA memory areas as the workload increases or decreases.
This process was introduced in Oracle 10g.

DBWR

The Database Writer writes dirty blocks from the database buffer to the datafiles. is determined by the Initialization parameter Initialization parameter DB_WRITER_PROCESSES determines on how many DBWn Processes are started . DBWR also writes the actual SCN with the Block and flushes datafile blocks.

LGWR
The Log Writer writes the redo log buffer from the SGA to the online redo log file. It wakes up for every three seconds to flush from the redo log buffer to the online redo logs or Whenever the redo log buffer is filled up to _log_io_size defaults to 1/3 of the log buffer size) and LGWR is not currently writing. This parameter is defined in units measured in physical operating system blocks, not DB blocks. The operating system block size is (obviously) OS dependent. It can be retrieved through x$kccle. This is called X$ table owned by SYS. The entire X$ tables are memory structures generated by Oracle when instance is spawned. They die with Instance. This is a separate discussion which we do later at another point of time.

RECO
The Distributed Transaction Recovery Process finds pending (distributed) transaction and resolves them.

CKPT
The Checkpoint Process regularly initiates a checkpoint, which uses DBWR to write all dirty blocks back to the datafiles, thus ensuring a consistent state to the database. Since a Checkpoint records the current SCN, in a recovery only redo records with a SCN higher than that of the last checkpoint need to be applied. The ckpt process also updates the datafile headers. The ckeckpoint process was optional in Oracle 7 (set CHECKPOINT_PROCESS=TRUE) and could be enabled to speed-up checkpointing on databases with a large number of files. Starting with Oracle 8i, the checkpoint process is automatically started with the other Oracle processes at instance startup.

ARCH
The Archiver Process archives redo log files if ARCHIVELOG is enabled. This means you have the capability of Media Recovery in case of failure.
Dnnn
The Dispatcher Process is used in a shared server environment. Dispatcher Processes, suppor multi-threaded configuration by allowing user processes to share limited number of server processes.

Snnn
The Shared Server Process is used in a shared server environment. shared Server Processes serve multiple client requests in the multi-threaded server configuration

LMON
The lock manager.

LMD0
AQ Time Manager

TRWR
Trace writer. The System Tracking process.

WMON
The wakeup monitor process.

LCKnnn
Inter-instance locking process.

SNPnnn
The snapshot process.

Qmnn (Queue Monitor)
Optional for Oracle Advanced Queuing which monitors the message queues. Used by Oracle Streams Advanced Queuing.
MMON
It makes snapshots of the database health (statistics) and stores this information in the automatic workload repository. MMON is also responsible for issuing alerts for metrics that exceed their thresholds.  This process was introduced in Oracle 10g.

Automated Storage Management ASM Instance Background Processes(10g)
Below provided are some new background processes added for an ASM instance

RBAL
This processes coordinates re-balance activity for disk groups. In an ASM instance coordinated rebalancing operations. In a DB instance, opens and mount diskgroups from the local ASM instance.

ARBx – Oracle backgroud processes. In an ASM instance, a slave for rebalancing operations

GMON – Oracle backgroud processes. In an ASM instance, diskgroup monitor.

ASMB – Oracle backgroud process. In an DB instance, keeps a (bequeath) persistent DB connection to the local ASM instance. Provides hearthbeat and ASM statistics. During a diskgroup rebalancing operation ASM communicates to the DB AU changes via this connection.

list of the new background processes in Oracle 11g:

VKTM
The virtual keeper of time provides wall-clock time and reference time for other sessions/processes.

FBAR  
The flashback data archiver writes old row-versions of tables with ‘flashback archive’ enabled into flashback data archives on commit.

DIAG
The diagnosibility process (DIAG) runs oradebug commands and triggers diagnostic dumps as part of the new ADR (automatic diagnostic repository) feature.

DIA0
The “other” diagnosibility process detects hangs then triggers DIAG do take diagnostics.

SMCO/Wnnn
The space management coordinator and slaves perform space allocation and reclamation.

There are many more. Please check below link to check various other back-end processes.

http://docs.oracle.com/cd/E14072_01/server.112/e10820/bgprocesses.htm

 

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ALTER SYSTEM SWITCH LOGFILE vs ALTER SYSTEM ARCHIVELOG CURRENT vs ALTER SYSTEM ARCHIVE LOG ALL

Posted by FatDBA on November 18, 2012

Both ALTER SYSTEM SWITCH LOGFILE and ALTER SYSTEM ARCHIVELOG CURRENT will force a log switch, but they do it in different ways.

ARCHIVELOG CURRENT waits for the writing to complete.  This can take several minutes for multi-gigabyte redo logs.  Conversely, the ALTER SYSTEM SWITCH LOGFILE command is very fast and returns control to the caller in less than a second while ALTER SYSTEM ARCHIVELOG CURRENT pauses.

  • ALTER SYSTEM  SWITCH LOGFILE is asynchronous:  This command is fast to return to the invoking program because the writing of the redo log to the OS filesystem is done in the background.  There is a very small risk in cases where the ARCH process cannot complete writing the redo log, such as cases where the OS archivelog file directory is out of space.  It is also risky because the calling script may move on to a subsequent step, assuming that the redo has been written.  Some scripts will place a SLEEP 60 command in their backup script to allow time for the redo to complete writing, but this is not a best practice.
  • ALTER SYSTEM ARCHIVELOG CURRENT is synchronous:  This is faster to return because this command waits until the online redo log has completed the writing of the redo log file to the filesystem.  This command is safer because it waits for the OS to acknowledge (ACK) that the redo log has been successfully written.  Hence, ALTER SYSTEM ARCHIVELOG CURRENT is the best practice for production backup scripts with RMAN.
  • ALTER SYSTEM ARCHIVE LOG ALL triggers an archive process if your DB (System) has archive logs that needs to be apply if still you try using the command you’ll receive below provided error message.

*
ERROR at line 1:
ORA-00271: there are no logs that need archiving

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SQLPLUS: Command Prompt customizied.

Posted by FatDBA on November 15, 2012

Some tips and tricks for SQLPLUS terminal:

———————————————————-
SQL Prompt With Time
———————————————————-
SQL> set time on
09:50:16 SQL>
09:50:19 SQL> select sysdate from dual;

SYSDATE
———
20-APR-11

09:50:34 SQL>

———————————————————-
SQL Prompt With USER
———————————————————-
SQL> set sqlprompt “_USER> ”
SCOTT>
SCOTT>
SCOTT> select sysdate from dual;

SYSDATE
———
20-APR-11

SCOTT>

———————————————————-
SQL Prompt With SID
———————————————————-
SQL> set sqlprompt “_CONNECT_IDENTIFIER> ”
mydb>
mydb>
mydb> select sysdate from dual;

SYSDATE
———
20-APR-11

mydb>

———————————————————-
SQL Prompt With USER@SID
———————————————————-
SQL> set sqlprompt “_USER’@’_CONNECT_IDENTIFIER SQL> ”
SCOTT@mydb SQL>
SCOTT@mydb SQL>
SCOTT@mydb SQL> select sysdate from dual;

SYSDATE
———
20-APR-11

SCOTT@mydb SQL>

———————————————————-
SQL Prompt With DATE
———————————————————-
SQL> set sqlprompt “_DATE SQL> ”
20-APR-11 SQL>
20-APR-11 SQL>
20-APR-11 SQL> select sysdate from dual;

SYSDATE
———
20-APR-11

20-APR-11 SQL>

 
Many More Soon!!!

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ORA-01555: Snapshot Too Old

Posted by FatDBA on November 7, 2012

Reasons:
The ORA-01555 error can occur when a long read only transaction is run against database
and there are many DML transactions being executed on database (on same data).
The longer query runs, there are more chances of encountering ORA-01555 exception.

The ORA-01555 is caused by Oracle “Read Consistency Mechanism”.
Oracle provides read consistency by reading the “before image” of updated data
from “Online UNDO Segments”. If there are lots of updates, long running read-only SQL
and a small UNDO, the ORA-01555 error may encounter.

ORA-01555 can be avoided by following precautions:
1. Database should be in Automatic Undo Management mode.
2. Use a large optimal value for undo_retention.
3. Use a large optimal size of rollback segment (undo) size.
4. Should Commit less often at the time of long running query, to reduce Undo Segment slot reuse.
5. Try to run long running queries on off peak hours, when there is less DML transactions

You can use the retention guarantee parameter (introduced in Oracle 10g) of the create UNDO Tablespace or alter UNDO Tablespace command, as shown in these examples:

-- Assumes OMF is configured.
Create UNDO Tablespace undotbs01
size 200m autoextend on
retention guarantee;

alter tablespace undotbs01 retention guarantee;

Use the alter tablespace retention noguarantee command to reset an UNDO Tablespace so that undo retention is no longer guaranteed.

Example:

— Reset the undo low threshold.
ALTER SYSTEM SET UNDO_RETENTION = 2400;

— Guarantee the minimum threshold is maintained.
ALTER TABLESPACE undotbs1 RETENTION GUARANTEE;

SELECT tablespace_name, retention FROM dba_tablespaces;

TABLESPACE_NAME                RETENTION
—————————— —————————————————————–
SYSTEM                             NOT APPLY
UNDOTBS1                       GUARANTEE
SYSAUX                            NOT APPLY
TEMP                               NOT APPLY
USERS                             NOT APPLY

5 rows selected.

— Switch back to the default mode.
ALTER TABLESPACE undotbs1 RETENTION NOGUARANTEE;

TABLESPACE_NAME                RETENTION
—————————— —————————————————————-
SYSTEM                            NOT APPLY
UNDOTBS1                       NOGUARANTEE
SYSAUX                            NOT APPLY
TEMP                               NOT APPLY
USERS                             NOT APPLY

5 rows selected.

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Recovery: Types ?

Posted by FatDBA on November 5, 2012

What Are the Types of Recovery?

There are three basic types of recovery: instance recovery, crash recovery, and media recovery. Oracle performs the first two types of recovery automatically at instance startup; only media recovery requires you to issue commands.

Instance Recovery
Instance recovery, which is only possible in an OPS (Oracle Parallel Server) configuration, occurs in an open database when one instance discovers that another instance has crashed. A surviving instance automatically uses the redo log to recover the committed data in the database buffers that was lost when the instance failed. Further, Oracle undoes any transactions that were in progress on the failed instance when it crashed and then clears any locks held by the crashed instance after recovery is complete.
Crash Recovery
Crash recovery occurs when either a single-instance database crashes or all instances of a multi-instance database crash. In crash recovery, an instance must first open the database and then execute recovery operations. In general, the first instance to open the database after a crash or SHUTDOWN ABORT automatically performs crash recovery.
Media Recovery
Unlike crash and instance recovery, media recovery is executed on your command. In media recovery, you use online and archived redo logs and (if using RMAN) incremental backups to make a restored backup current or to update it to a specific time. It is called media recovery because you usually perform it in response to media failure. Media recovery is a process of restoring the physical backups and making all the restored datafiles consistent with each other by having same SCN’s in their header’s.

If you do not use Recovery Manager (RMAN) to perform recovery, then you should use the SQL*Plus RECOVER command. It is also possible to use the SQL statement ALTER DATABASE RECOVER, but it is highly recommended that you use the SQL*Plus RECOVER command instead.

When using SQL*Plus to perform media recovery, the easiest strategy is to perform automatic recovery. Automatic recovery initiates recovery without manually prompting SQL*Plus to apply each individual archived log.

When using SQL*Plus, you have two options for automating the application of the default filenames of archived redo logs needed during recovery:

  • Issuing SET AUTORECOVERY ON before issuing the RECOVER command – SET AUTORECOVERY ON  – >  RECOVER DATABASE
  • Specifying the AUTOMATIC keyword as an option of the RECOVER command   – RECOVER AUTOMATIC DATABASE

 

what are the types of media recovery in oracle database?

  1. Complete recovery
  2. Incomplete recovery

Though it is complete recovery or incomplete recovery, the recovery types classified based on what type of failure we are going to recover.

  1. Full database recovery
  2. Tablespace recovery
  3. Datafile recovery
Types of Media recovery
Complete Recovery Incomplete Recovery
Complete Recovery involves recovery of database with out any data loss i.e full recovery. Making all datafiles consistent with each other i.e having latest SCN and opening database normally with out resetlogs option. Incomplete Recovery means recovering database to a specified time, SCN no, log sequence no or using cancel. In this type of recovery the database can open only with RESETLOG option and database can not open normally.

What is complete media recovery?

Complete media recovery is process of restoring full database, a tablespace or a datafile from backup based upon media failure and applying the redo log files to the most current time with of loosing any data’s.

To determine which files to recover:

SQL> SELECT * FROM v$recover_file;

FILE#      ONLINE  ERROR              CHANGE#    TIME     
---------- ------- ------------------ ---------- ---------
        14 ONLINE                              0          
        15 ONLINE  FILE NOT FOUND              0          
        21 OFFLINE OFFLINE NORMAL              0

When you perform complete recovery, you can either recover the whole database at once or recover individual tablespaces or datafiles. Because you do not have to open the database with the RESETLOGS option after complete recovery as you do after incomplete recovery, you have the option of recovering some datafiles at one time and the remaining datafiles later. Types of recoveries comes under Complete Media Recovery:

  • Performing Closed Database Recovery
  • Performing Open Database Recovery

How complete full database media recovery are made (Performing CLOSED DATABASE Recovery)?

Following way of complete full database recovery is used in both operating system command along with sqlplus recovery command or RMAN utility.

    • Shutdown your database using SHUTDOWN ABORT option
    • Mount the Database using STARTUP MOUNT
    • Restore all the datafiles from the backup and make all datafiles online.
    • Apply online redo log files or archived redo log files or both.
    • open the database with below command.

sql>alter database open;

How complete tablespace or datafile recovery made (Performing  OPEN DATABASE recovery) ?

Following methods applies to both operating system commands along with Sqlplus RECOVERY command or RMAN utility method to recover datafile or tablespace.

    • During database open take tablespace or datafile which need recovery offline.
    • Restore the backup tablespace or datafile.
    • Apply the online redo log files or archive redo log files or both.
    • Open the database with below command.

sql>alter database open;

How incomplete recovery done in oracle database?

Incomplete recovery in oracle database are done using following option when applying archived redo log files and online redo log files.

  1. Time based recovery
  2. Cancel based recovery
  3. Change based recovery
  4. Log sequence recovery

The recover database until  command supports three clauses that will abort the recovery process at a specified point:

  • recover database until time  ‘YYYY-MM-DD:HH24:MI:SS’ recovers the database to a specified point in time.
  • recover database until cancel recovers the database applying one log file at a time until the recovery process is manually canceled
  • recover database until change <scn>recovers the database to a specified system change number ( SCN)

After using any one option open the database with following commands,

sql>alter database open resetlogs;

The above statement reset the log sequence to 0 and this command is used when we need incomplete recovery.

What are the methods of media recovery available in oracle database?

  1. Recovery using operating system.
  2. RMAN Recovery Manager.
Methods of Media recovery
Using Operating system commands and sqlplus RECOVERY command RMAN (Recovery Manager)
This old traditional method of physical backup and recovery available in oracle. From oracle 9i onwards oracle recommends to use RMAN which overcomes the disadvantages in backup and recovery using operating system commands. Since backup taken with OS commands can be used with RMAN utility. But backup taken with RMAN cannot used with OS commands for media recovery directly. RMAN means recovery manager to define it in simple words like logical utility (import,impdp) this is physical backup and recovery utility comes along with oracle database software. This makes oracle database server itself to take backup and recovery it during failure. This backup information are stored in target(backup) database control file and catalog database scheme(optional one if it is used).

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Oracle Big Data: What’s the Hype …

Posted by FatDBA on November 5, 2012

“Oracle Big Data: A revolution that has already begun … ”

Read About It:

wp-bigdatawithoracle-1453236

bigdataappliance-datasheet-1453665

big-data-strategy-guide-1536569

managing_bd_w_hadoop_exadata

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Point-In-Time Recovery Tablespaces (Using RMAN)

Posted by FatDBA on November 4, 2012

Point In Time recovery for Tablespaces also known as TSPITR allows you to recover one of more tablespaces to any past time.

Deciding When to Use TSPITR
Like a table import, RMAN TSPITR enables you to recover a consistent data set; however, the data set recovered includes an entire tablespace rather than one object.

RMAN TSPITR is most useful for situations such as these:

  • Recovering data lost after an erroneous TRUNCATE TABLE statement;
  • Recovering from logical corruption of a table;
  • Recovering a logical schema to a point different from the rest of the physical database, when multiple schemas exist in separate tablespaces of one physical database.

Note that, as with database point-in-time recovery (DBPITR), you cannot perform TSPITR if you do not have your archived redo logs. For databases running in NOARCHIVELOG mode, you cannot perform TSPITR. You can only restore your entire database from a consistent backup.

Limitations of TSPITR
There are a number of situations which you cannot resolve by using TSPITR.

  • You cannot recover dropped tablespaces.
  • You cannot recover a renamed tablespace to a point in time before it was renamed. If you try to perform a TSPITR to an SCN earlier than the rename operation, RMAN cannot find the new tablespace name in the repository as of that earlier SCN (because the tablespace did not have that name at that SCN).
  • You cannot recover tables without their associated constraints, or constraints without the associated tables.
  • Tablespaces that contain objects owned by SYS, including rollback segments..

RMAN > Recover tablespace DIXIT until time
“to_date(‘2009-08-04 12:15:00’,’YYYY-MM-DD HH24:MI:SS’)”
auxiliary destination ’/opt/oracle/temp’;

Once the above statement is executed, RMAN does the following for us:

  • Creates auxiliary instance (including the pfile etc..)
  • Mounts the auxiliary instance
  • Makes the candidate tablespace into OFFLINE
  • Restores the basic tablespace UNDO, SYTEM,SYSAUX and then the required tablespace
  • Applies archives (completes recovery)
  • Opens the database
  • Performs an export of the objects residing in the tablespace
  • Shutdown aux instance
  • Import the objects into the target database
  • Remove aux instance and cleanup

 

That’s all and you now have all the objects back in the tablespace lost!.

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Oracle Secure Backup: Configuration

Posted by FatDBA on October 31, 2012

  • Steps to Configure Oracle Secure Backup (OSB):

Step 1. As the root user, check if the uncompress utility is installed on the system. If it is not,
create a symbolic link pointing to the gunzip utility:

(This is an important per-requisite and this is needed by the installed to uncompress files to installation directory and Mostly this does not comes pre-installed with Linux OS, create symbolic link with the Gunzip utility or install an RPM for this)
[root@lin32 ~]# uncompress
-bash: uncompress: command not found
[root@lin32 ~]# ln -s /bin/gunzip /bin/uncompress
Step 2. Create a directory for the download, and then issue the change directory command to
that directory:
[root@lin32 ~]# mkdir download
[root@lin32 ~]# cd download/
Step 3. Download OSB into the download directory and then unzip the product:
[root@lin32 download]# ls –l
total 43864
-rw-r–r– 1 root root 44866571 Jan 19 20:31 osb-10.3.0.1.0_linux32_release.zip
[root@lin32 download]# unzip osb-10.3.0.1.0_linux32_release.zip
Archive: osb-10.3.0.1.0_linux32_release.zip
creating: osb-10.3.0.1.0_linux32_cdrom090504/
extracting: osb-10.3.0.1.0_linux32_cdrom090504/OSB.10.3.0.1.0_LINUX32.rel
creating: osb-10.3.0.1.0_linux32_cdrom090504/doc/
creating: osb-10.3.0.1.0_linux32_cdrom090504/doc/dcommon/
creating: osb-10.3.0.1.0_linux32_cdrom090504/doc/dcommon/css/
inflating: osb-10.3.0.1.0_linux32_cdrom090504/doc/dcommon/css/blafdoc.css
inflating: osb-10.3.0.1.0_linux32_cdrom090504/doc/dcommon/css/bp_layout.css
…
inflating: osb-10.3.0.1.0_linux32_cdrom090504/welcome.html
inflating: osb-10.3.0.1.0_linux32_cdrom090504/doc.tar
Step 4. Create the directory where the install will place OSB files:
[root@lin32 download]# mkdir -p /usr/local/oracle/backup

Step 5. Issue the change directory command to the OSB destination and run setup:
[root@lin32 download]# cd /usr/local/oracle/backup/
[root@lin32 backup]# /root/download/osb-10.3.0.1.0_linux32_cdrom090504/setup
The following output is returned:
Welcome to Oracle’s setup program for Oracle Secure Backup. This program loads
Oracle Secure Backup software from the CD-ROM to a filesystem directory of your
choosing.
This CD-ROM contains Oracle Secure Backup version 10.3.0.1.0_LINUX32.
Please wait a moment while I learn about this host… done.
– – – – – – – – – – – – – – – – – – – – – – – – – – –
1. linux32
administrative server, media server, client
– – – – – – – – – – – – – – – – – – – – – – – – – – –
Loading Oracle Secure Backup installation tools… done.
Loading linux32 administrative server, media server, client… done.
– – – – – – – – – – – – – – – – – – – – – – – – – – –
Oracle Secure Backup has installed a new obparameters file.
Your previous version has been saved as install/obparameters.savedbysetup.
Any changes you have made to the previous version must be made to the new obparameters file.
Would you like the opportunity to edit the obparameters file
Please answer ‘yes’ or ‘no’ [no]:
Step 6. Leaving the default parameters for now, press ENTER to choose the default answer. The
following output is returned:
– – – – – – – – – – – – – – – – – – – – – – – – – – –
Loading of Oracle Secure Backup software from CD-ROM is complete.
You may unmount and remove the CD-ROM.
Would you like to continue Oracle Secure Backup installation with ‘installob’ now?
(The Oracle Secure Backup Installation Guide contains complete information about
installob.)
Please answer ‘yes’ or ‘no’ [yes]:
Step 7. Again, press ENTER to choose the default answer. The following output is returned:
– – – – – – – – – – – – – – – – – – – – – – – – – – –
Welcome to installob, Oracle Secure Backup’s installation program.
For most questions, a default answer appears enclosed in square brackets.
Press Enter to select this answer.
Please wait a few seconds while I learn about this machine… done.
Have you already reviewed and customized install/obparameters for your Oracle
Secure Backup installation [yes]?
Step 8. Again, press ENTER to choose the default answer and to leave the default parameters. The
following output is returned:
– – – – – – – – – – – – – – – – – – – – – – – – – – –
Oracle Secure Backup is not yet installed on this machine.
Oracle Secure Backup’s Web server has been loaded, but is not yet configured.
Choose from one of the following options. The option you choose defines the
software components to be installed.

Configuration of this host is required after installation completes.
You can install the software on this host in one of the following ways:
(a) administrative server, media server and client
(b) media server and client
(c) client
If you are not sure which option to choose, please refer to the Oracle Secure
Backup Installation Guide. (a,b or c) [a]?
Step 9. You are going to install all three components of OSB on the same server, so again press
ENTER to choose the default answer. The following output is returned:
Beginning the installation. This will take just a minute and will produce
several lines of informational output.
Installing Oracle Secure Backup on lin32 (Linux version 2.6.18-53.el5)
You must now enter a password for the Oracle Secure Backup encryption key store.
Oracle suggests you choose a password of at least 8 characters in length,
containing a mixture of alphabetic and numeric characters.
Please enter the key store password:
Re-type password for verification:
Step 10. Enter the OSB encryption key twice. The key is not displayed. You will see the
following output:
You must now enter a password for the Oracle Secure Backup ‘admin’ user. Oracle
suggests you choose a password of at least 8 characters in length, containing a
mixture of alphabetic and numeric characters.
Please enter the admin password:
Re-type password for verification:
Step 11. Enter the admin password twice. The password is not displayed. You will see the
following output:
You should now enter an email address for the Oracle Secure Backup ‘admin’ user.
Oracle Secure Backup uses this email address to send job summary reports and to
notify the user when a job requires input. If you leave this blank, you can set it
later using the obtool’s ‘chuser’ command.
Please enter the admin email address:
Step 12. Leave the e-mail address blank for now. The following output is returned:
generating links for admin installation with Web server
updating /etc/ld.so.conf
checking Oracle Secure Backup’s configuration file (/etc/obconfig)
setting Oracle Secure Backup directory to /usr/local/oracle/backup in /etc/obconfig
setting local database directory to /usr/etc/ob in /etc/obconfig
setting temp directory to /usr/tmp in /etc/obconfig
setting administrative directory to /usr/local/oracle/backup/admin in /etc/obconfig
protecting the Oracle Secure Backup directory
creating /etc/rc.d/init.d/observiced
activating observiced via chkconfig
initializing the administrative domain
****************************** N O T E ******************************
On Linux systems Oracle recommends that you answer no to the next two questions.
The preferred mode of operation on Linux systems is to use the /dev/sg devices for

attach points as described in the ‘ReadMe’ and in the ‘Installation and
Configuration Guide’.
Is lin32 connected to any tape libraries that you’d like to use with Oracle Secure Backup [no]?
Is lin32 connected to any tape drives that you’d like to use with Oracle Secure
Backup [no]?
Step 13. Since, in this example, you use a Linux system, answer “no,” as recommended by
Oracle, and configure the media server later. The following summary is returned:
Installation summary:
Installation Host OS Driver OS Move Reboot
Mode Name Name Installed? Required? Required?
admin lin32 Linux no no no
Oracle Secure Backup is now ready for your use.
The OSB administrative server, media server, and client are now installed. The OSB Web tool
is used to configure the tape library and tape drives.

Once configured launch your Web browser and supply the URL of the host running Oracle Secure Backup. Use the following syntax, where hostname can be a fully qualified domain name:

https://hostname
https://localhost.localdomain

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Oracle Secure Backup ?

Posted by FatDBA on October 31, 2012

What is Oracle Secure backup ?
Oracle Secure Backup is centralized tape backup management software providing secure data protection for heterogeneous file systems and the Oracle Database. Oracle has its own media management software solution, Oracle Secure Backup (OSB). OSB is a fully integrated, RMAN-to-tape solution that does not require any third-party vendor software plug-in, and OSB has come a long way since its introduction in 10gR2.

In Oracle 10gR2 and Oracle 11g, you can utilize OSB to provide free backup to tape functionality, provided that you have a single tape head and it is attached directly to the server that contains the Oracle database that you want to back up. In addition to tape backup, OSB delivers an integrated Oracle database backup to third-party cloud (Internet) storage, through the Oracle Secure Backup Cloud Module. Oracle Secure Backup offers two tape management editions: OSB and OSB Express.

Oracle Secure Backup Interfaces:
You can interact with Oracle Secure Backup by means of the following tools:
– Oracle Secure Backup Web tool
– Oracle Secure Backup command-line interface
– Oracle Enterprise Manager

OSB Roles and Admin Domains:
Administrative server:
Each administrative domain must have exactly one administrative server. This server stores data pertinent to the operation of the administrative domain in a set of configuration files. Metadata relating to backup and restore operations is also stored on the administrative server in a backup catalog.
The administrative server runs the scheduler, which starts and monitors jobs within the administrative domain.

Media Server
A media server has one or more secondary storage devices, such as a library and tape drives, connected to it. At a minimum, a media server must have one standalone tape drive. Many media servers utilize robotic tape libraries.

Client
A client host is a host that has locally-accessed data that is backed up or restored by Oracle Secure Backup. Any host where Oracle Secure Backup is installed, or that contains data that Oracle Secure Backup accesses through Network Data Management Protocol (NDMP), can act as a client. Each client host is associated with one administrative server.

 

 

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Standby: Protection Modes.

Posted by FatDBA on October 30, 2012

The protection modes run in the order from highest (most data protection) to the lowest (least data protection):

Minimum Requirements for Data Protection Modes
Maximum Protection Maximum Availability Maximum Performance
Redo Archival Process LGWR LGWR LGWR or ARCH
Network Transmission Mode SYNC SYNC ASYNC when using LGWR process. Not applicable when using ARCH process.
Disk Write Option AFFIRM AFFIRM NOAFFIRM
Standby Redo Logs Required? Yes Required for physical standby databases only. Standby redo logs are not supported for logical standby databases. Required for physical standby databases using the LGWR process.
Database Type Physical only Physical and Logical Physical and Logical

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