11g r2 data guard setup

[jackb]

Hi,

Could you please explain why in this article http://www.oracle-base.com/articles/11g ... _11gR2.php you create Standby Redo Logs on Primary Server. I am not getting it

Is it so that you don't have to create them in the standby? Why did you create 4 of them? What rule do you follow? The same number as the primary?

Thank you.

[Tim...]

Hi.

Standby redo logs on the primary, ready for a switchover, where the primary becomes the standby.

There should always be 1 more standby redo log group than there are online redo log groups. I had three online redo log groups, so 4 standby. This is explained in the article:

http://www.oracle-base.com/articles/11g ... o_logs_man

Cheers

Tim...

[jackb]

Yes, thank you, it is now clear.

But if I have a RAC like that?

Code: Select all

SQL> select max (bytes)/1024/1024 MB, count (1) from v$log;

        MB   COUNT(1)
---------- ----------
      1024          4

SQL> select GROUP#, THREAD#, MEMBERS, ARCHIVED, STATUS from v$log;

    GROUP#    THREAD#    MEMBERS ARC STATUS
---------- ---------- ---------- --- ----------------
         1          1          2 YES INACTIVE
         2          1          2 NO  CURRENT
         3          2          2 YES INACTIVE
         4          2          2 NO  CURRENT

I should do that?

alter database add standby logfile thread 1 group 6 '+dgfraelo/el_stby/standbylog/standby_group_06.log' size 1024M;
alter database add standby logfile thread 1 group 7 '+dgfraelo/el_stby/standbylog/standby_group_07.log' size 1024M;
alter database add standby logfile thread 1 group 8 '+dgfraelo/el_stby/standbylog/standby_group_08.log' size 1024M;
alter database add standby logfile thread 2 group 9 '+dgfraelo/el_stby/standbylog/standby_group_09.log' size 1024M;
alter database add standby logfile thread 2 group 10 '+dgfraelo/el_stby/standbylog/standby_group_10.log' size 1024M;
alter database add standby logfile thread 2 group 11 '+dgfraelo/el_stby/standbylog/standby_group_11.log' size 1024M;

Is it right?

[Tim...]

Hi.

The number of standby redo logs is:

((number of online redo logs per thread) + 1) * (number of threads)

So in your case you have 2 redo logs per thread and 2 threads, so (2+1)*2=6.

Cheers

Tim...

[jackb]

So what I did is correct?

[Tim...]

Yes. I thought was pretty obvious based on what I answered. Obviously not.

[jackb]

Thank you Tim.

[Tim...]

[jackb]

It gets a bit complicated creating a data guard with 2 RACs

[Tim...]

Hi.

The extra steps necessary should be documented in the manuals.

Cheers

Tim...