Re: Mirroring redo log groups or not ?
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_at_vishalgupta.com> 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.
> Vishal Gupta
> *From:* oracle-l-bounce_at_freelists.org on behalf of Tim Gorman
> *Sent:* Wed 08/04/2009 00:51
> *To:* hkchital_at_singnet.com.sg
> *Cc:* mwf_at_rsiz.com; david.barbour1_at_gmail.com; Jon.Crisler_at_usi.com; '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_at_EvDBT.com
> 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>
> > --
> > http://www.freelists.org/webpage/oracle-l
-- Martin Berger martin.a.berger_at_gmail.com Lederergasse 27/2/14 +43 660 660 83306 1080 Wien http://berx.at/ Sent from Wien, Österreich -- http://www.freelists.org/webpage/oracle-lReceived on Wed Apr 08 2009 - 07:21:04 CDT