Re: Mirroring redo log groups or not ?

  • From: Martin Berger <martin.a.berger@xxxxxxxxx>
  • To: vishal@xxxxxxxxxxxxxxx
  • Date: Wed, 8 Apr 2009 14:21:04 +0200

fuser (or similar tools) is your friend before deleting files. (for many
reasons)

but back to the OP:
  one additional point in your environment is the HBA/Network part: If you
have mirrored logfiles, you write every bite twice
  (regardless on which LUN, the bits have to use the HBAs and Network).
  I could not find any information in the posts if this can be a bottleneck
in your environment, just keep it in mind.



On Wed, Apr 8, 2009 at 11:19, Vishal Gupta <vishal@xxxxxxxxxxxxxxx> wrote:

>  I would expect any sysadmin worth their money to search for files based
> on modification time rather creation time. And for an active database online
> redo log will always have the modification time of today.
>
> But yes, there is are people who may consider even log files to be useless.
> But in my opinion log files should not be simply deleted. Rather log files
> older than certain date should be deleted. As log contain lot of important
> troubleshooting information when investigating a problem which occured
> sometime in past.
>
>  Regards,
> Vishal Gupta
> http://www.vishalgupta.com
>
> ------------------------------
> *From:* oracle-l-bounce@xxxxxxxxxxxxx on behalf of Tim Gorman
> *Sent:* Wed 08/04/2009 00:51
> *To:* hkchital@xxxxxxxxxxxxxx
> *Cc:* mwf@xxxxxxxx; david.barbour1@xxxxxxxxx; Jon.Crisler@xxxxxxx; 'Rajeev
> Prabhakar'; 'Oracle-L Freelists'
> *Subject:* Re: Mirroring redo log groups or not ?
>
>  One situation I've witnessed....
>
> A lot of people create the online redo log files with the file-extension
> of ".log".  A lot of SysAdmins have a "cron"-initiated script that
> removes files named ".txt", ".log", ".lst", etc that are older than N
> days old from certain file-systems, or sometimes when a file-system is
> filling up someone will run a "find" command to find big text files
> (i.e. ".log" is a good candidate) and get rid of them.  Put the two
> together and you've got the perfect storm.
>
> For my part, I always use the file-extension of ".rdo" or just plain old
> ".dbf", but never ".log".  Of course, someone can still remove files
> with those extensions, but I feel the probability is smaller...
>
> Tim Gorman
> consultant - Evergreen Database Technologies, Inc.
> P.O. Box 630791, Highlands Ranch CO  80163-0791
> website   = http://www.EvDBT.com/
> email     = Tim@xxxxxxxxx
> mobile    = +1-303-885-4526
> fax       = +1-303-484-3608
> Yahoo IM  = tim_evdbt
>
>
>
> Hemant K Chitale wrote:
> > VERY TRUE.  I've never bought the argument that mirroring online redo
> logs is a protection from DBA error.
> >
> > ---  wrote:
> > There is no protocol that can protect you from human error bysomeone with
> > authority to remove an online log file.
> >
> > <snip>
> >
> >
> > --
> > //www.freelists.org/webpage/oracle-l
> >
> >
> >
> >
> >
> --
> //www.freelists.org/webpage/oracle-l
>
>
>


-- 
Martin Berger           martin.a.berger@xxxxxxxxx
Lederergasse 27/2/14           +43 660 660 83306
1080 Wien                                       http://berx.at/
Sent from Wien, Österreich

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