Re: retention policy for rman backup
- From: "Maris Elsins" <elmaris@xxxxxxxxx>
- To: ora-apps-dba@xxxxxxxxxxxxx
- Date: Thu, 24 Jan 2008 01:57:30 +0200
Hi,
It's not meaningless to keep backups more than 3 days. It actually doesn't
meter how old the backups are. If you have all the archived redo logs since
that backup, you will be able to recover using that backup, just the
recovery will take longer as you'll have to apply all the archived redos
since then. And as older your backup are as more archived redo logs you have
to keep to be able to recover, which requires more space on tapes and
increases risk that some archived redo log may become corrupt (during
copying for example) and some problems can arise during recovery.
There has to be some backup&recovery strategy put in place before getting to
RMAN configuration. And the main idea is to have the strategy which meets
the business requirements like:
- how far into past we have to be able to recover?
- what's the allowable resource consumption during backuping?
- what's the maximum allowable recovery time?
- what's the risk we can take on backup media failures (e.g corruption on
tapes)?
- etc
when the business requirements are defined, you can answer more technical
questions like
* how many backup copies do we keep?
* how old backups do we keep?
* do we keep any backups on the server locally?
* when do we do full backups and when incremental?
* how often do we backup archived redo logs?
* how many copies of archived redo logs do we store?
* how many times do we reuse the tapes?
* which backups we store onsite and which do we store offsite?
...etc
And if we set 3 days for retention policy now according to answers on
questions above and the backups get deleted after 3 days, we know without
doubt that this is because it's no longer needed to meet the business
requirements..
best regards,
Maris Elsins
On Jan 23, 2008 2:53 PM, Kenan Öztürk <mynameiskenan@xxxxxxxxx > wrote:
> Hi all,
>
> I am confused about something, I am configuring retention policy to 3
> days, and rman deleting backups that are older than 3 days, because they
> seem obsolete according to retention policy.
>
> But what i want to learn is if it is possible to use backups that are
> older than 3 days, in case of disaster ?? or is it meaningless to keep
> backup files that are older than 3 days?
>
> Regards,
> Kenan
>
>
> ------------------------------
> Looking for last minute shopping deals? Find them fast with Yahoo!
> Search.<http://us.rd.yahoo.com/evt=51734/*http://tools.search.yahoo.com/newsearch/category.php?category=shopping>
>
--
br,
Maris Elsins
Other related posts:
