Re: One control file/redo member with ASM ok?

From: Thomas Kyte <tkyte_at_oracle.com>
Date: 16 Jan 2005 16:39:42 -0800
Message-ID: <115922381.000156ea.045@drn.newsguy.com>

In article <beolu01umcqbaft3pmdmu5isst1c4as0bg_at_4ax.com>, Sybrand Bakker says...
>
>On 16 Jan 2005 10:25:25 -0800, domenicg_at_hotmail.com (Domenic) wrote:
>
>>Is it acceptable to use one control file and one redo log member only
>>(per group) on a database using ASM, where ASM is doing the mirroring?
>> What's Oracle's recommendation/opinion on this? Wouldn't two control
>>files and two redo members per group be overkill when ASM is doing the
>>mirroring also?
>>
>>Domenic.
>
>Oracle requires 2 control files. It won't start without 2 control
>files.
>Mirroring only protects you against hardware failure.
>It doesn't protect you against someone inadvertently deleting a
>controlfile.
>Also the controlfile is usually only a few Mb's big. It would be very
>strange to try to save a few Mb's and instead increase the risk
>someone blows up your database.
>
>
>--
>Sybrand Bakker, Senior Oracle DBA

Really?

SQL> startup pfile=initora9ir2.ora
ORACLE instance started.  

Total System Global Area 269554828 bytes

Fixed Size                   451724 bytes
Variable Size             201326592 bytes
Database Buffers           67108864 bytes
Redo Buffers                 667648 bytes

Database mounted.
Database opened.
SQL> show parameter control  

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
control_file_record_keep_time        integer     7
control_files                        string      /home/ora9ir2/oradata/ora9ir2/
                                                 control01.ctl

SQL> (they have the control files mirrored via ASM mirroring)

-- 
Thomas Kyte
Oracle Public Sector
http://asktom.oracle.com/
opinions are my own and may not reflect those of Oracle Corporation

Received on Sun Jan 16 2005 - 18:39:42 CST