RE: Mirroring redo log groups or not ?
- From: "Mark W. Farnham" <mwf@xxxxxxxx>
- To: <kennaim@xxxxxxxxx>, <david.barbour1@xxxxxxxxx>, <Jon.Crisler@xxxxxxx>
- Date: Tue, 7 Apr 2009 20:35:39 -0400
This calls for analysis. Now why exactly were there copies of the redo logs
on a drive shared with dynamically extending logs?
Hmm. Were perchance the "primary" copies of the logs on a properly allocated
database file system with no competition from things not database, but
someone decided it would be "safer" to have multiple members in the log
groups? Unfortunately the only place to put the extra members was a bad
place.
But you let that fellow retain access to your production systems? I hope
retraining was involved, though often the shock of the experience is taken
for training enough. I would not want to go hunting with such a person.
mwf
_____
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of Kenneth Naim
Sent: Tuesday, April 07, 2009 7:50 PM
To: mwf@xxxxxxxx; david.barbour1@xxxxxxxxx; Jon.Crisler@xxxxxxx
Cc: 'Rajeev Prabhakar'; 'Oracle-L Freelists'
Subject: RE: Mirroring redo log groups or not ?
I've had an admin "cleanup" a filesystem that was filling up by removing all
*.log files, since the other redo file were on separate filesystems we were
protected and so was his job. We also name our redo logs with a .ora
extension now.
Ken
_____
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of Mark W. Farnham
Sent: Tuesday, April 07, 2009 7:04 PM
To: david.barbour1@xxxxxxxxx; Jon.Crisler@xxxxxxx
Cc: 'Rajeev Prabhakar'; 'Oracle-L Freelists'
Subject: RE: Mirroring redo log groups or not ?
There is no protocol that can protect you from human error by someone with
authority to remove an online log file.
I'd actually be surprised if there was someone dumb enough to remove active
online logs and not anal enough to remove all the copies. But we'll never
know, because you're positing that the folks who removed single member log
groups would have been saved by multiple members. Unless you have a time
machine, you cannot test that.
Regards,
mwf
_____
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of David Barbour
Sent: Tuesday, April 07, 2009 2:22 PM
To: Jon.Crisler@xxxxxxx
Cc: Rajeev Prabhakar; Oracle-L Freelists
Subject: Re: Mirroring redo log groups or not ?
Mirroring protects you from more than disk failure, it also protects you
from human error. Please, mirror your logs. There is a long history
littered with un-employed DBAs backing this recommendation.
<snip>
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