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RMAN Backup

User_U9EN2
User_U9EN2 Member Posts: 20 Blue Ribbon
edited Jan 11, 2020 3:00PM in Recovery Manager (RMAN)

Hi All,

How to speed up RMAN backups for VLDBs' like 20 TB. ?

Is taking full backups or tablespace wise backups better.

Also when running long RMAN jobs, can we get the ESTIMATED time for finish...

Thanks

Answers

  • Dude!
    Dude! Member Posts: 22,829 Black Diamond
    edited Jan 11, 2020 9:54AM

    There's not much info to work with here. Nobody can guess what you have available from a software, hardware, and license perspective. There are plenty of ways to improve backup performance, such as block change tracking (BCT), multi-section backup, etc, however, the solution is not software only, but also requires the necessary support of your hardware.

    Whether you do full backups only, or another strategy, will be an evaluation between resources and time required for backup and the requirements for restore and recovery. You usually start by defining your recovery requirements, then find a suitable backup strategy to accomplish the goal.

    You can query the v$session_longops view to query time estimates, for example:

    alter session set NLS_DATE_FORMAT = 'DD-MM-YYYY HH24:MI:SS';

    SELECT opname,

           sysdate "Current Time", start_time "Start Time",

           sysdate + time_remaining/3600/24 "Estimate Finish"

    FROM   v$session_longops

    WHERE  sofar <> totalwork

           AND opname NOT LIKE '%aggregate%'

           AND opname like 'RMAN%';

  • User_U9EN2
    User_U9EN2 Member Posts: 20 Blue Ribbon
    edited Jan 11, 2020 10:17AM

    I am planning to do a "Tablespace" level backup for the 1st time, Cannot use advanced license features.

    Oracle version 11gR2 on redhat linux. CPU=2, Threads/CPU=8. RAM=128gb.

  • Dude!
    Dude! Member Posts: 22,829 Black Diamond
    edited Jan 11, 2020 3:00PM

    That's not enough information.

    Where are you storing the backup and recovery data?

    What is the reason for doing a tablespace backup?

    How are you going to restore or recover a tablespace from backup if you loose the database?

    If you're planning to create a new database and then restore tablespaces from RMAN tablespace backup, that's not possible.