RE: How do you test your backups?
- From: "Mark W. Farnham" <mwf@xxxxxxxx>
- To: <howard.latham@xxxxxxxxx>, "'ORACLE-L'" <oracle-l@xxxxxxxxxxxxx>
- Date: Thu, 30 Jan 2014 12:29:30 -0500
If you only have the single alternate system and not enough space to add a
duplicate but your disk volume is external redundancy raid 10 (or anything
with at least two full plexes) you can temporarily shut down recovery (keep
shipping the logs), peel a plex off making an unprotected volume (which you
just use or present to ASM as a different disk group, lying about it being
externally redundant). Then recover to that disk group and spin it up. This
minimizes the excess hardware cost, but it more complicated for you.
If you only have the single alternate system and plenty of space, you do as
above but skipping the deplexing. You probably want space free on a recovery
(standby) server anyway to cover the case where you're not sure whether a
logical attack has already been applied to the standby, so you want to begin
recovery to a safe point in time from RMAN while you investigate. You still
have to shut down your normal standby because of the database and instance
name thing. You probably want to unmount your normal diskgroup as well to
avoid hilarity.
If you have multiple alternate systems, then it gets easier as you can match
up production-standby pairs with other pairs having excess storage space for
test recovery targets. That eliminates the need for shutting down standby
due to a duplicate name problem and the possibility of inadvertently
trashing your normal disk group. Or a single extra machine to serially do
test RMAN recoveries for any production server. Then all you need is the
available storage. If the intent is only to test the backup's integrity (as
distinct from the standby's integrity), then a blown "tape test" due to a
disk crash should not be an issue, so you can single plex the disk group for
the recovery test (again lying about external redundancy, at least to
Oracle's ASM). [Of course I always suggest keeping the test space available
as at least raid 10 because even a testing system disk loss is annoying and
time consuming, but I understand folks have some pretty doggone big
databases out there.]
Good luck,
mwf
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of Howard Latham
Sent: Thursday, January 30, 2014 8:02 AM
To: ORACLE-L
Subject: How do you test your backups?
Oracle 11g Linux 4.
I'm reviewing my backup strategy and wondered if anyone had any clever ideas
for backup testing.
I was thinking of trashing my standby and trying to reinstate it from my
RMAN backup on tape. I think this would prove
a serviceable database can be built from tape.
--
Howard A. Latham
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